What is a planet beyond our solar system called?

A planet beyond our own solar system is referred to as an exoplanet. While most exoplanets orbit other stars, there are also free-floating exoplanets, called rogue planets, that are not tethered to any star and orbit the galactic centre.

"Blind" surveys

Traditionally, ground-based means have been employed to detect exoplanets. Astronomers use "blind" surveys to look for stars in the sky with the potential for housing giant planets, which can then be directly imaged from Earth based on the stars age and distance. This technique, however, has a very low yield, meaning that exoplanets are detected very infrequently. Astronomers have developed a new technique to detect exoplanets whose portraits can be taken using large ground-based telescopes on Earth. They have tasted success with this method and the result is the direct image of a Jupiter-like gas giant - HIP 99770 b-132.8 light years away in the Cygnus constellation. The study behind this success was published in the journal Science in April.

Combining astrometry and direct imaging

HIP 99770 b is the first exoplanet detected by combining astrometry and direct imaging. While two observatories on Hawaii Island did the direct imaging, the astrometry- responsible for measuring the position and motion of HIP 99770 b's home star - came from Gaia space observatory and its predecessor Hipparcos.

Precision astrometry is the method of detecting the movement of stars. This allows researchers to identify those stars that are tugged at by the gravitational pull of an unseen companion like a planet. A picture of the star systems that are close enough is then captured to directly image.

The detection of HIP 99770 b serves as proof of a concept developed by an international research team. They were also able to determine that this exoplanet is 14-16 times the mass of Jupiter and orbits a star that is almost twice as massive as our sun. It receives a similar amount of light as Jupiter as its host star is far more luminous than the sun. The team characterised the nature of HIP 99770 b's atmosphere and showed that the planet's atmosphere has signs of water and carbon monoxide.

This new method of searching for exoplanets is believed to be a major improvement to the existing, traditional method of "blind" surveys. The researchers also hope that this new approach would lead to further advances that eventually lead to the discovery of an Earth-twin around a nearby star.

Picture Credit : Google 

What are UFOs?

Hundreds of new UFO reports, but...there is still no evidence of aliens. The Pentagon, the headquarters of the United States Department of Defense, has set up a new office to track reports of UFO sightings and collect data.

What are UFOs?

A new Pentagon office set up to track reports of unidentified flying objects (UFOS) has received "several hundreds" of new reports. What are UFOS? Over the centuries, people have reported seeing strange airborne objects or unusual optical phenomena in the sky. These are called UFOS. Over the years, the belief that UFOs are the spaceships of aliens from other planets has gained ground - though without any concrete evidence. Are there possibilities of extraterrestrial life? Shouldn't the sightings be tracked systematically? Well, that's why the All-domain Anomaly Resolution Office (AARO) was formed.

2. What is AARO?

The AARO was set up in July 2022 to track unidentified objects in the sky, underwater and in space. It was established following more than a year of attention on unidentified flying objects that military pilots have observed.

It focusses on unexplained activity around military installations, restricted airspace and "other areas of interest" and is aimed at helping identify possible threats to the safety of U.S. military operations and to national security.

3. Scientific approach

Sean Kirkpatrick, director, AARO, did not rule out the possibility of extraterrestrial life and said he was taking a scientific approach to the research. Since the launch of the AARO, there have been several hundred new reports.

"We are structuring our analysis to be very thorough and rigorous. We will go through it all. And as a physicist, I have to adhere to the scientific method."

4. No alien life

The U.S. military officially calls the 144 sightings observed between 2004 and 2021 as "unidentified aerial phenomena."

But they have seen nothing that indicates alien life. "I have not seen anything that would suggest that there has been an alien visitation, an alien crash or anything like that," said Ronald Moultrie, Under Secretary of Defense for Intelligence and Security.

5. Quick facts

The Air Force conducted an investigation into UFO activity called 'Project Blue Book’. It ended in 1969 with a list of 12,618 sightings, 701 of which involved objects that officially remained "unidentified."

In 1994, it concluded that the 1947 famous "Roswell incident" in New Mexico, was not an UFO but a crashed balloon, the military's long-standing explanation.

Picture Credit : Google 

What does a dust devil sound like on Mars?

Mars rover’s microphone captures ten seconds of rumbling noise created by dust devil on the Red Planet. It's the same microphone that provided the first sounds of Martian wind in 2021.

What does a dust devil sound like on Mars? A NASA rover by chance had its microphone on when a whirling tower of red dust passed directly overhead, recording the racket.

It's about 10 seconds of not only rumbling gusts of up to 40 kph, but the pinging of hundreds of dust particles against the rover Perseverance. Scientists released the first-of-its-kind audio. It sounds strikingly similar to dust devils on Earth, although quieter since Mars' thin atmosphere makes for more muted sounds and less forceful wind, according to the researchers.

The dust devil came and went over Perseverance quickly last year, thus the short length of the audio, said the University of Toulouse's Naomi Murdoch, lead author of the study appearing in Nature Communications.

At the same time, the navigation camera on the parked rover captured images, while its weather-monitoring instrument collected data.

"It was fully caught red-handed by Persy," said co-author German Martinez of the Lunar and Planetary Institute in Houston.

Photographed for decades at Mars but never heard until now, dust devils are common at the red planet.

This one was in the average range: at least 400 feet (118 metres) tall and 80 feet (25 metres) across, travelling at 16 feet (5 metres) per second.

The microphone picked up 308 dust pings as the dust devil whipped by, said Murdoch, who helped build it.

Given that the rover's SuperCam microphone is turned on for less than three minutes every few days, Murdoch said it was "definitely luck" that the dust devil appeared when it did on Sept. 27, 2021. She estimates there was just a 1-in-200 chance of capturing dust-devil audio. Of the 84 minutes collected in its first year, there's "only one dust devil recording," she wrote in an email from France.


  • Common across Mars, dust devils are short-lived whirlwinds loaded with dust that form when there is a major difference between ground and air temperatures.
  • They are a common feature in the Jezero crater, where the Perseverance rover has been operational since February 2021 - but it had never before managed to record audio of one of them.
  • By chance on September 27, 2021, a dust devil 118 metres high and 25 metres wide passed directly over the rover.
  • This time, the microphone on the rover's SuperCam managed to catch the muffled, whirring sounds.

Sounds...so far

  • The same microphone on Perseverance's mast provided the first sounds from Mars namely the Martian wind soon after the rover landed in February 2021.
  • It followed up with audio of the rover driving around and its companion helicopter, little Ingenuity, flying nearby, as well as the crackle of the rover's rock-zapping lasers, the main reason for the microphone.


On the prowl for rocks that might contain signs of ancient microbial life, Perseverance has collected 18 samples so far at Jezero Crater, once the scene of a river delta. NASA plans to return these samples to Earth a decade from now. Its helicopter Ingenuity has logged 36 flights, the longest lasting almost three minutes.


  • These recordings allow scientists to study the Martian wind, atmospheric turbulence and now dust movement as never before.
  • The impact of the dust-made "tac tac tac sounds will let researchers count the number of particles to study the whirlwind's structure and behaviour.
  • It could also help solve a mystery that has puzzled scientists. On some parts of Mars, whirlwinds pass by sucking up dust, cleaning the solar panels of rovers along the way.
  • Understanding why this happens could help scientists build a model to predict where the whirlwinds might strike next.
  • It could even shed light on the great dust storms that sweep across the planet, famously depicted in the 2015 science-fiction film "The Martian".

Picture Credit : Google 

What is Kuiper Belt?

Also called the "third zone" of the solar system, this large volume of space outside Neptune's orbit is home to thousands of icy, cold objects. This is where Pluto is also present.

In the cold, outermost area of our solar system lies one of the largest structures in our solar system. Also called the "third zone" of the solar system, this "donut-shaped" volume of space is called the Kuiper belt. This is where Pluto is also present.

The region encompasses hundreds of thousands of icy, cold objects and is outside Neptune's orbit.

The region is named so after astronomer Gerard Kuiper, who published a paper speculating objects beyond Pluto. This was also suggested by Astronomer Kenneth Edgeworth in the papers he published and sometimes this belt is called the Edgeworth-Kuiper Belt. Some researchers also refers to it as the Trans-Neptunian Region.

The icy bodies are called Kuiper Belt Objects (KBOS) or trans-Neptunian objects (TNOS). They are highly diverse in terms of size, shape, and colour. A significant number of KBOS have moons.

So how did the icy objects form? According to scientists, these icy objects are leftovers after the formation of our solar system. The region must have formed after these objects came together to form a planet but Neptune's gravity played spoilsport. The gravity shook up this region and these icy objects couldn't join to form a planet.

The Kuiper Belt volume is being lost nowadays. The amount of material which it carries now is much less when compared to what it contained earlier.

The objects in the belt collide and lead to fragmented, smaller objects. Sometimes the dust gets blown out of the solar system. We take a look at a few of the KBOS.


This KBO is known for its strange shape and rotation style. According to NASA, the Haumea resembles a squashed American football. This was a result of the object's collision with another object half the size of it.


Smaller than Pluto, Eris takes 557 years to orbit the Sun. It has a moon called Dysnomia.


Lying some billion miles past Pluto is the Arrokoth, a Kuiper Belt Object which means sky in the Native American language. This small snowman-shaped object is believed to hold clues about the origin of life on Earth and also about the planet's formation.

Picture credit : Google 

What was the mission of the Hubble Space Telescope?

A mission conceived as one for preventive maintenance turned out to be more urgent after four of the six gyroscopes on board the Hubble space telescope failed.

The Hubble space telescope has changed our understanding of the universe A telescope that was launched into low Earth orbit in 1990, Hubble still remains operational and continues to be a vital research tool. Following NASA's most recent review of Hubble's operations, it has been announced that NASA would support the observatory through June 2026, with estimates suggesting that it might be able to continue operations until the mid-2030s and even beyond.

Designed to be visited

While the longevity of the telescope is testament to the vision of those who conceived the mission, there's another crucial factor that has made it possible. Hubble was the first telescope that was designed to be visited in space. This meant that astronauts could not only perform repairs and replace parts, but also upgrade its tech with newer instruments. There have been five such missions that have taken place from 1993 to 2009. One such servicing mission in December 1999 turned out to be a life saver for the telescope.

After the first servicing mission in 1993 and the second one in 1997, the third to carry out preventive repairs was scheduled for June 2000. Since Servicing Mission 2 in February 1997, however, three of the six gyroscopes aboard Hubble had failed. With at least three working gyroscopes necessary for Hubble's operation, it prompted the managers to split Servicing Mission 3 (SM3) into two parts, SM3A and SM3B, with the former scheduled for December 1999.

An unexpected failure

 On November 13, 1999, a fourth gyroscope failed unexpectedly. With SM3A planned for the following month, this triggered NASA to place Hubble into safe mode. The safe mode was a sort of protective hibernation that prevented the telescope from making any observation. Hubble was in this state for over a month, waiting for the crew of SM3A to make their way.

With servicing mission veterans Steven Smith and Michael Foale at the helm, the seven-member crew aboard the Discovery Space Shuttle (STS-103) left for space on December 19. Within a couple of days, they manoeuvred close enough to Hubble such that it could be grappled with Discovery's robotic arm.

All six gyroscopes replaced

 The first of the three scheduled spacewalks took place over 8 hours and 15 minutes spanning December 22-23 (Central European Time, CET). Smith, along with fellow crew member John Grunsfeld, managed to replace all six of Hubble's gyroscopes. The entire astronomical community heaved a collective sigh of relief on receiving this news. The duo also replaced kits to prevent Hubble's batteries from overcharging.

While Hubble's main computer was changed in the second spacewalk that spanned 8 hours 10 minutes through December 23-24 (CET), the final spacewalk spanning 8 hours 8 minutes through December 24-25 (CET) saw a faulty transmitter and data tape recorder being replaced. Preliminary tests were then conducted to ensure that all of Hubble's systems, be it old or new, were performing satisfactorily.

Backs away slowly

Minutes into December 26 (CET), the Hubble telescope was released. Discovery then backed away from Hubble slowly. Having successfully performed the major objectives of the mission, the astronauts on board used the time remaining to stow away equipment, apart from making preparations for landing.

After orbiting the Earth 119 times and travelling more than 5 million km, Discovery made its way back. It performed a smooth night-time landing, touching down on the runway at the Kennedy Space Center in the U.S. on December 27. Hubble was successfully back in operation, and has been for over two decades since then.

Picture Credit : google 

Which is the first comet to encounter a spacecraft?

Discovered first on December 20, 1900, comet 21P/Giacobini-Zinner gets its name from two astronomers. From being one of the last comets to be discovered in the 19th Century, this comet is now best known for having the first encounter with a spacecraft.

Comets are popular for different reasons. There's Halley's comet, which is the most famous of them all. Regularly visible to the naked eye from the Earth, Halley's comet has been observed and recorded by astronomers for over 2,000 years. Then, there is comet Hyakutake. Discovered only in 1996, this comet's passage near the Earth in the same year was one of the closest cometary approaches in nearly 200 years. We will be turning our attention to comet 21P/Giacobini-Zinner, whose claim to fame now includes being the first comet to encounter a spacecraft. This comet was first discovered on December 20, 1900, making it one of the last comets to be discovered in the 19th Century. A discoverer of a number of comets, French astronomer Michel Giacobini found this comet while skygazing from Nice Observatory. It was followed for two months and orbital calculations revealed that the comet was a periodic object with an orbital period less than seven years.

Recovered in 1913

It wasn't recovered in 1907, when it was not placed favourably for viewing. Even though the comet was expected to be unfavourably placed in 1914 as well, German astronomer and renowned science historian Ernst Zinner accidentally rediscovered it on October 23, 1913.

Since both Giacobini and Zinner discovered and recovered this comet, it is named after them and is called comet 21P/Giacobini-Zinner. The letter "p" indicates that it is a periodic comet, which are comets with orbital periods less than 200 years. When orbital calculations were revised when the comet was recovered in 1913, its orbital period was found to be close to 6.6 years, and the comet has been observed on almost every return since then.

Draconid meteor shower

This comet had favourable returns in 1959, 1985, and 2018, when it was well observed as its perihelion (closest approach to sun) allowed it to pass close to the Earth. The nucleus of the Giacobini-Zinner sprays ice and rock into space every time it returns to the inner solar system. This makes the comet the parent comet of the Draconid meteor shower, which takes place in early October each year.

While this meteor shower is quite weak in most years, there have been Draconic meteor storms on record, meaning that over 1,000 meteors were seen per hour at the location of the observer. The 1933 and 1946 Draconid storms were particularly intense, with over 500 meteors observed per minute in Europe during the former and 50-100 per minute seen in the U.S. during the latter.

Farquhar's idea

Comet Giacobini-Zinner's current claim to fame was a result of its favourable return in 1985. When funding for a spacecraft mission to comet 1P/Halley, which was enroute to its 1986 perihelion passage, didn't materialise, planetary scientist Robert Farquhar came up with an idea. He suggested that the already existing International Sun-Earth Explorer 3 (ISEE-3) be placed on an alternate path that would take it towards Giacobini-Zinner.

Once the idea was approved, ISEE-3 was sent on a series of lunar flybys that would take it towards Giacobini-Zinner. Following the final lunar flyby in December 1983, ISEE-3 was renamed the International Cometary Explorer (ICE).

On September 11, 1985, ICE passed through the ion tail of Giacobini-Zinner, thereby completing the first encounter between a comet and a spacecraft. While ICE lacked cameras, it did carry scientific instruments that enabled it to record measurements of the electric environment around the comet and also as to how the comet interacted with the solar wind.

Even though an international fleet of spacecraft, including ICE, met Halley in 1986 from a number of vantage points for a study like never before, Giacobini-Zinner will forever hold the title of being the first comet to encounter a spacecraft. While its most recent return in 2018 might be comet 21P's most favourable return in the 21st Century, you can still look forward to its approach once in less than seven years, and maybe even try and track it.

Picture Credit : Google 

A black hole in Earth's backyard?

This new black hole is 1.600 light-years away in the constellation Ophiuchus So far scientists have discovered 20 black holes in the Milky Way. About 100 million more are estimated to be present in our galaxy.

A new black hole has been discovered very near to Earth, closer than any other previously found. Christened Gaia BH1, this dormant blackhole is 1.600 light-years away in the constellation Ophiuchus.

This new black hole is ten times as massive as our sun. To date, scientists have found 20 black holes in the Milky Way galaxy whilst 100 million more are estimated to be present in our galaxy. The newly discovered one is three times closer than the earlier black hole which sat about 3,000 light-years away in the constellation Monoceros.

Since there are more undetected black holes, even this newly discovered one wouldn't hold its spot of "closest to Earth" for too long.

The discovery was mentioned in a paper in the peer-reviewed Monthly Notices of the Royal Astronomical Society. The black hole was discovered by "Kareem El-Badry, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics and his colleagues.

They found evidence of the existence of this dormant black hole using the data from the European Space Agency's GAIA (Global Astrometric Interferometer for Astrophysics) spacecraft. After they noticed a star in the constellation Ophiuchus moving in unexpected ways, they understood that it was a result of the gravity of an unknown, massive object. Using the observation from other telescopes, they confirmed that the object causing this was a black hole.

What is a Black Hole

A black hole is a celestial body that has an immensely huge gravitational pull, so huge that nothing escapes it. Not even light can escape i it!

The black hole grows by accumulating matter that falls in it. Black holes are formed at the end of the life of a big star. When a massive star collapses after its nuclear fuel depletes, it will collapse onto itself and become a black hole.

 It was in 2019 that an image of a black hole was captured for the first time. It was an international collaboration and the astronomers used the Event Horizon Telescope (EHT), networking eight ground-based radio telescopes.

Picture Credit : Google 

What are dwarf galaxies?

As their name suggests, dwarf galaxies are smaller galaxies. In contrast to a normal galaxy that comprises hundreds of billions of stars, a dwarf galaxy would contain just about a few billion stars. These dwarf galaxies orbit larger galaxies after their formation.

Formation of dwarf galaxies

The dwarf galaxies are created when two galaxies collide, fromed from the material and dark matter coming out of the galaxies that collided.

Following these collisions, while a significant portion of the gas, dust and stars emitted gets reincorporated into the galaxy created after the collision, some can lead to the formation of dwarf galaxies which then orbit around the galaxy. They are also formed by the gravitational forces existing during the creation of these larger galaxies.

Why are dwarf galaxies crucial

Scientists consider the dwarf galaxies critical as they could help gain insight into the early stages of the formation of galaxies and stars. According to scientists, our galaxy has about 14 satellite dwarf galaxies orbiting it.

Studies are being carried out on these dwarf galaxies as it would give us clues regarding the evolution of the galaxies. By studying the motion of the stars in these galaxies, we would also get to know more about dark matter and how it is distributed in the galaxies.

It is difficult to spot dwarf galaxies as they are less bright when compared to larger galaxies. A large number of them can be spotted in galaxy clusters or as a companion to larger galaxies.

Shapes of dwarf galaxies

The dwarf galaxies take several shapes. The dwarf elliptical galaxies are quite similar to normal elliptical galaxies.

Then there are dwarf spheroidal galaxies which are more spherical in shape and smaller when compared to the former.

Then we have the irregular dwarf galaxies. They do not have a distinct structure and are rich in gas.

One of the closest dwarf galaxies to the Milky Way is the Sagittarius Dwarf Spheroidal Galaxy.

Picture Credit : Google 

Is a missing moon responsible for Saturn's rings and tilt?

Now known to host at least 83 moons, researchers propose that Saturn at one point must have had at least one more satellite, which they call Chrysalis

While all four gas giants - Jupiter, Saturn, Uranus, and Neptune - have rings, Saturn is the most popular ringed-planet. Swirling around Saturn's equator, these rings indicate clearly that the planet is spinning at a tilt relative to the plane in which it orbits the sun.

For a long time, astronomers have suspected that this tilt is the result of Saturn's interactions with neighbouring Neptune. A new modelling study by astronomers at Massachusetts Institute of Technology (MIT). however, suggests that while the two planets may have been in sync before, Saturn has since escaped Neptune's pull.

Call it Chrysalis

 In a study appearing in Science in September, the MIT team

posits that a missing moon might be responsible for this planetary realignment. Now known to host at least 83 moons, Saturn at one point must have had at least one more satellite that the researchers call Chrysalis.

The team estimates that after orbiting Saturn for several billion years, Chrysalis became unstable about 160 million years ago, coming too close to Saturn in the process. As the proposed satellite was long dormant before suddenly becoming active - just like a butterfly's chrysalis - the researchers gave it the name Chrysalis.

The resulting encounter pulled the satellite apart and the loss of the moon was enough for Saturn to escape

Neptune's grasp and leave it with its current tilt. Additionally, the researchers suggest that while most of Chrysalis' shattered body may have impacted Saturn, a fraction of its fragments could have remained suspended in orbit. These could then have broken into small icy chunks to form the planet's standout rings.

Explains two mysteries

The missing moon hypothesis, the researchers believe, could thus explain two mysteries pertaining to Saturn's system. While one of these is Saturn's present-day tilt, the other one is the age of its rings.

The rings are estimated to be about 100 million years old. very much younger than the planet itself. If the rings were indeed formed from fragments of Chrysalis, then the story fits perfectly.

Cassini's inputs

The team of researchers arrived at this hypothesis by modelling the interior of Saturn. They identified a distribution of mass that matched the gravitational field that was observed by the Cassini spacecraft in its final phases. What they found indicated that Saturn is no longer in sync with Neptune, paving the way for researching various hypotheses, before arriving at their final result. The lead author of the study says that it is "a pretty good story, but like any other result, it will have to be examined by others".

Picture Credit : Google 

How did Japan's Hayabusa spacecraft collect samples from an asteroid?

Scientists study meteorites for clues about the origin of Earth and the solar system because most meteorites are bits of asteroids that have fallen to Earth, and asteroids are believed to be leftover material from the time the solar system formed.

In 2005, for the first time ever, scientists scooped up rock samples directly from an asteroid using a spacecraft built especially for that purpose. The name of the spacecraft was Hayabusa. It was a robotic spacecraft developed by the Japan Space Exploration Agency (JAXA).

Hayabusa (Japanese for falcon') was launched on May 9, 2003, and arrived in the vicinity of the asteroid Itokawa in mid-September 2005. In November 2005, it landed on the asteroid and collected samples in the form of tiny grains of rock which it brought back to Earth on June 13, 2010. Hayabusa was the first spacecraft to land and take off from an asteroid.

In December 2014, Japan launched another spacecraft Hayabusa 2 to study the near-Earth asteroid Ryugu and to bring back samples of rock not only from its surface but also from deeper below the surface. Hayabusa 2 reached Ryugu in June 2018.

In September 2018, the spacecraft landed two rovers on the asteroid. They were the first rovers ever to move on an asteroid. They moved with a hopping movement instead of rolling around on wheels. The rovers are designed to take pictures of the landscape and measure the temperatures on the asteroid.

Hayabusa 2 left the asteroid in November-December 2019 and delivered a small capsule that contained the rock and dust samples when it was 220,000 km from the Earth's atmosphere. The capsule safely landed in the South Australian outback in December 2020.

Picture Credit : Google 

Is Earth the only planet that supports life?

Discovery about an Earth-like planet orbiting an M dwarf could imply that planets orbiting the most common star may be uninhabitable.

Is Earth the only planet that supports life? This is one of the many questions for which we don't have an answer yet. In a universe filled with countless stars and innumerable planets, our quest for life on a planet other than our own continues.

A new discovery could serve as a signpost and maybe even dramatically narrow our search for life on other planets. The discovery, explained in the Astrophysical Journal Letters in October by researchers from the University of California - Riverside, reveals that an Earth-like planet orbiting an M dwarf appears to have no atmosphere at all.

Most common type of star M dwarfs or red dwarfs are the most common type of star in the universe. This discovery could therefore imply that a large number of planets orbiting these stars may also lack atmospheres, and will therefore likely not support life.

The planet named GJ 1252b is slightly larger than our Earth, but is much closer to its star, an M dwarf, than the Earth is to the sun. On a single day on Earth, this planet orbits its star twice.

In order to find out if this planet lacks an atmosphere, astronomers measured infrared radiation from the planet as its light was during a secondary eclipse. In a secondary eclipse, the planet passes behind the star, and hence the planet's light along with the light reflected from its star are blocked.

Scorching temperatures

The radiation revealed the planet's daytime temperatures to be of the order of 2,242 degrees Fahrenheit. This, along with assumed low surface pressure, led the astronomers to believe that GJ 1252b lacks an atmosphere.

The researchers concluded that the planet will not be able to hold on to an atmosphere, even if it had tremendous amounts of carbon dioxide, which traps heat. Even if an atmosphere builds up initially, it would taper off and erode away eventually.

With M dwarf stars having more flares, the likelihood of planets surrounding them closely holding onto their atmospheres goes down further. The lack of atmosphere means that life as we know it is unlikely to flourish.

In Earth’s  solar neighbourhood, there are about 5,000 stars and most of them are M dwarfs. If planets surrounding them can be ruled -out entirely in the search for life based on this discovery, that would leave roughly around 1,000 stars similar to the sun that could be habitable.

For now, however, these can't be ruled out entirely. Nor can we rule out the possibility of a planet far enough away from an M dwarf star such that it retains its atmosphere. We need more research and results as we continue to embark on our search for life elsewhere.

Picture Credit : Google 

What are brown dwarfs?

Brown dwarfs are also known as failed stars. Why? Find out

Brown dwarfs are celestial objects that are too large to be called planets and too small to be called stars. They have. a mass less than 0.075 that of the sun, which is around 75 times the mass of Jupiter. Like stars, brown dwarfs are believed to form from a collapsing cloud of gas and dust. But as the cloud collapses, it does not form an object dense enough at its core to trigger a nuclear fusion. In the case of a star, hydrogen is converted into helium by nuclear fusion. This is what fuels a star and causes it to shine. Brown dwarfs, on the other hand, are not massive enough to ignite fusion. Hence, they are also called ‘failed stars’.

Dimmer and cooler than stars, brown dwarfs are elusive and hard to find. Infrared sky surveys and other techniques have, however, helped scientists detect hundreds of them.

They are believed to be as common as stars in the Universe. Some of them are companions to stars and many are isolated objects.

First discovered in 1995, brown dwarfs were hypothesized in 1963 by American astronomer Shiv Kumar. Despite their name, brown dwarfs are not brown. They appear from deep red to magenta, depending on their temperature.

Picture Credit : Google 

Why did the Mars Observer fail?

On August 22, 1993, just days before the Mars Observer spacecraft was to enter orbit around Mars, it lost contact with the bases here on Earth. The $400 million spacecraft with an estimated overall project cost of $1 billion was designed to study and photograph the Martian surface, but ended in failure.

Following the success of the Mariner programme in the 1960s and early 70s, the Viking programme was the U.S.'s next foray towards our neighbouring planet, Mars. After the probes Viking 1 and Viking 2 successfully landed on the red planet in 1976, over a decade went by before America's next mission to Mars. That came in the way of the Mars Observer, which was launched in 1992 and had things going well until its ill-fated end.

The mid-1980s saw a high priority mission to Mars being planned to act and expand on the information already assimilated by the Viking programme. With the preliminary mission goals of studying and taking high-resolution photographs of the Martian surface, the Mars Observer spacecraft was initially to be launched in 1990, before being rescheduled to 1992.

Based on Earth-orbiting spacecraft

Based on a commercial Earth-orbiting communications satellite that had been converted into an orbiter for Mars, the spacecraft was built at a cost of $400 million. The payload was made up of a variety of instruments that included a Gamma Ray Spectrometer (GRS), Pressure Modulator Infrared Radiometer (PMIRR), Thermal Emissions Spectrometer (TES), Mars Observer Camera (MOC), and Mars Balloon Relay (MBR) among others.

The specific objectives of the mission were to find out the elemental characteristics of the Martian surface: defining Mars topography and gravitational field: establishing the nature of Mars magnetic field finding out the distribution and sources of dust and volatile material over a seasonal cycle: and exploring the Martian abmosphere. The MBR was designed to receive information from the planned Mars Balloon Experiment to be carried by a Russian mission for retransmission back to Earth.

Contact lost

The Mars Observer was expected to achieve all this by orbiting the planet for one Martian year (687 Earth days), giving it a chance to observe the planet through the different seasons. The science instruments in the payload were thus designed to study the geology, climate, and geophysics of Mars.

Following a successful launch on September 25, 1992, Mars Observer was scheduled to perform an orbital insertion manoeuvre 11 months later on August 24, 1993. Just days before it, however, on August 22, 1993, communication was lost with the spacecraft even as it was preparing to enter orbit.

When the Mars Observer failed to respond to messages radioed by the ground controllers here on Earth, further efforts to communicate were made-once every 20 minutes. Even though they were met with silence, further attempts were made, less regularly, until the mission was declared a loss on September 27, 1993 and no further attempts to contact were made after that

Propulsion system failure

In 1994, an independent board from the Naval Research Laboratory announced their findings regarding the failure. They suggested that the most probable cause of the communications failure must be a rupture of the fuel pressurisation tank in the propulsion system of the spacecraft

Regardless of what the reason was, an estimated cost of $1 billion, which included the price of the spacecraft along with the costs of space shuttle launching and processing of scientific data was lost. While the science instruments were reflown on two other orbiters, Mars Global Surveyor and 2001 Mars Odyssey, there is no telling if Mars Observer followed the automatic programming to go into Mars orbit flew by the planet, or even if it continues to operate.

Picture Credit : Google 


If we talk about ringed planets, more often than not every one of us will be talking about Saturn. This, despite the fact that all four giants in our solar system Jupiter, Saturn, Uranus, and Neptune - in fact have rings.

This is likely because Saturn has spectacular rings. While the rings of Jupiter and Neptune are flimsy and difficult to view with stargazing instruments traditionally used, the rings of Uranus aren't as large as that of Saturn's.

As Jupiter is bigger than Saturn, it ought to have rings that are larger and more spectacular than that of its neighbour. As this isn't the case, scientists from UC Riverside decided to investigate it further. Their results were accepted by the Planetary Science journal and are available online.

Dynamic simulation

A dynamic computer simulation was run to try and understand the reason why Jupiter's rings look the way they do. The simulation accounted for Jupiter's orbit, the orbits of Jupiter's four main moons, and information regarding the time it takes for rings to form.

The rings of Saturn are largely made of ice, some of which may have come from comets also largely made of ice. When moons are massive, their gravity can either clear the ice out of the planet's orbit, or change the ice's orbit such that it collides with the moons.

Massive moons

The Galilean moons of Jupiter Ganymede, Callisto, lo, and Europa- are all large moons. Ganymede, in fact, is the largest moon in our solar system. The four main massive moons of Jupiter would thus destroy any large rings that might form around the planet. This also means that Jupiter is unlikely to have had large. spectacular rings at any time in the past as well.

Ring systems, apart from being beautiful, help us understand the history of a planet. They offer evidence of collisions with moons or comets, indicating the type of event that might have led to their formation. The researchers next plan to use the simulations to study the rings of Uranus to find out what the lifetime of those rings might be.

Picture Credit : Google 


Scientists have achieved yet another historic feat by discovering a dormant black hole. It is for the first time that a dormant stellar-mass black hole orbiting a star has been detected in a nearby galaxy.

This new black hole is nine times the mass of the Sun and revolves around a blue star in the nearby Large Magellanic Cloud galaxy. Researchers have termed it "the first to be unambiguously detected outside our galaxy". The binary system has been christened VFTS243. This finding is cardinal because it will help us get more insights into what happens during the death of a star and how black hole pairs are formed.

Astrophysicist and the lead author of the new study Tomer Shenar remarked that they have found a 'needle in a haystack. The study was published in the Nature Astronomy journal.

How it was detected

In a binary system, two stars revolve around each other and when a star dies, it will lead to a black hole in orbit with the other companion star. Scientists detect black holes from the X-ray radiation they emit as they feed on the companion star.

In this case, the scientists found a massive star orbiting something that couldn't be observed.

Following further studies, scientists found out that it was a dormant black hole.

The stellar mass black holes are formed when a massive star dies and collapses in a supernovae explosion. But strangely, in this particular case, the star that led to the formation of the black hole in VFTS 243 went away without any explosion and literally vanished into a black hole. Scientists have termed it a direct-collapse scenario. This has led scientists to understand that all stars do not end their lives in supernova explosions and it gives insight into how black hole pairs are formed.

What is a Black Hole?

A black hole is a celestial body that has an immensely huge gravitational pull, so huge that nothing escapes it. Not even light can escape it! The black hole grows by accumulating matter that falls in it. An image of a black hole was captured for the first time in 2019.

What is the size of a Black Hole?

The tiniest black hole can be as tiny as an atom but it can have the mass of a huge mountain. The other is the stellar black hole and these can have a mass of more than 20 solar masses, which is 20 times more mass than our sun. And the biggest black holes are christened supermassive. Sagittarius A is a supermassive black hole.

How are Black Holes formed?

Black holes are formed at the end of the life of a big star. When a massive star, say one having more than 20 solar masses, collapses after its nuclear fuel depletes, it will collapse onto itself and become a black hole. This collapse leads to a supernova and a part of the star gets blown off into space.

So will our Sun turn into a Black Hole?

The Sun cannot turn into a black hole. For us, the Sun is big, but on a celestial scale, it is too small to collapse into a black hole! So, our Sun will only turn into a white dwarf.

Picture Credit : Google