My Science School

The Chandrayaan-2, the second lunar exploration mission after Chandrayaan-1 that has been developed by the Indian Space Research Organisation (ISRO), has been in orbit around the moon for over two years now. During a Lunar Science Workshop that was held early in September 2021, ISRO chairman K Sivan stated that the spacecraft has completed over 9.000 orbits around the moon

Launched on July 22 2019, the Chandrayaan-2 mission consisted of a lunar orbiter, along with the Vikram lander and the Pragyan lunar rover. Having reached the moon's orbit on August 20 2019, it then positioned itself for Vikram's landing.

Landing failure

The landing, scheduled for September 6 2019, however, turned out to be a failure. Even though Vikram was on track and performed as expected till, kilometres away from the lunar surface, it then lost communications with the ground stations and had a hard landing on the moon. The landing failure thus meant that the Vikram lander and the Pragyan rovers were a failure. Even though the landing phase of the Chandrayaan-2 mission was a failure, the orbiter continued to go around the moon. This means that the eight instruments onboard have been able to study the moon, both using remote sensing and in-situ techniques.

Chromium and manganese

One of the most important findings from these observations for over two years is the presence of chromium and manganese on the moon's surface. Not only were the presence of these elements revealed, but the weight of these components as a percentage of the weight of the moon was also determined.

Apart from revealing these findings in the workshop in September 2021, it was also conveyed that raw data is continuously being made available in the public domain. Sivan made it clear that Chandrayaan-2's data is "national property" and has urged the entire scientific community of the country to put it to good use and further our knowledge of the moon.

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On September 15, SpaceX’s first private flight launched into space successfully. Called Inspiration4, it was the first time a spacecraft circled Earth with an all-amateur crew and no professional astronauts. It's yet another milestone in the space tourism market. Earlier this year, billionaire businessmen Sir Richard Branson and Jeff Bezos went above Earth's atmosphere in their own space vehicles. (SpaceX's next private trip, early next year. will see a retired NASA astronaut escorting three wealthy businessmen to the space station for a week-long visit. The Russians are launching an actress, a film director and a Japanese tycoon to the space station in the next few months.) Want to learn more about the Inspiration4 mission? This week's Five Ws and One H will get you all the details.

What is Inpiration4?

The Inspiration4 mission w the brainchild of Jared Isaacman, the billionaire CEO of Shift4 Payments, a online payments company, who bought all four seats aboard the Dragon Capsule for an undisclosed hefty sum from SpaceX (Some reports put the price at $50 million per seat). The mission blasted off in the Falcon 9 rocket. The Dragon capsule, where the crew sat during the orbit, was modified for this flight. A huge glass done the largest ever space window was installed  to offer passengers a 360 degree view of space. The dome replaced the al mechanism used on Dragons to dock with the International Space Station (ISS)

The Dragon capsule orbited earth for three days at a high altitude of 585 km 160 km higher than the 155. The mission was commanded by lsaacman, who is also an accomplished pilot and adventurer.

What is the aim of the flight?

The trip was designed with the explicit intent to benefit St. Jude Children's Research Hospital, which treats and researches childhood cancers and other diseases. Started by an initial $100 million gift from Isaacman to St. Jude, inspirations has fundraising goal to raise $200 million through February 2022 to help accelerate rah advancements and  save more children worldwide. The mission has a commitment of more than $130 million with auction items related to the mission.

Why is the mission special?

The inspirations mission marks several historic milestones for human space exploration. It was the first  all-civilian crew to orbit earth, the first free flight Crew Dragon mission, and the first orbital human spaceflight mission that did not dock with a space station since the final Hubble mission on STS-125 in 2009.

Who are the crew members?

Joining the mission commander Jared Isaacman (38) on the trip are crew pilot Sian Proctor (51), who is a geoscientist, science communicator and artist Hayley Arceneaux (29), a childhood bone cancer survivor who works as a physician assistant where she was treated - St. Jude Children's Research Hospital in Memphis, Tennessee; and mission specialist Chris Sembroski (42), a U.S. Air Force veteran and a data engineer from North Carolina. Sian Proctor was, in fact, a finalist to become a NASA astronaut more than a decade ago.

How were the crew members selected? Isaacman donated two of the seats to St. Jude hospital. For one seat, the hospital selected Hayley Arceneaux and for the other, it conducted a raffle as part of a campaign to raise funds for the hospital. An undisclosed person from Embry-Riddle Aeronautical University ultimately won the raffle, but decided for personal reasons to give the seat to his friend, Sembroski, who was also one of 72.000 entrants in the raffle. Sian Proctor was selected by Shift4 Payments through a competition that rewarded the best business idea to make use of Shift4's commerce solutions.

What did the team do on the flight?

The crew took part in a health research initiative to increase humanity's knowledge on the impact of spaceflight on the human body. Once in orbit the crew performed carefully selected research experiments on human health and performance. The crew members' sleep, heart rate, blood and cognitive functions were analyzed during the mission in order to study how rookies react in space.

A series of tests through an app to assess changes in behavioral and cognitive performance were done. This is the same app that is currently used by astronauts in NASA-funded research studies.

Markers of immune function and inflammation were monitored. Balance and perception tests pre-flight and immediately post-flight were measured to study the sensorimotor adaptation during changes of gravity. In addition, SpaceX collaborated with investigators at Weill Cornell Medicine to perform a longitudinal, multi-omic analysis of the crew, including genome and spatial transcriptome analysis.

These samples and data will be added to a planned Biobank that will hold samples of the human, microbial, and environmental specimens that are collected before, during, and after missions and enable long-term research and health monitoring for astronauts and space travellers.

How did the crew undergo training?

Though the capsule is automated, the four Dragon riders spent six months training for the flight to cope with any emergency. It included centrifuge training, Dragon simulations, observations of other launch operations, Zero-G plane training and altitude training.

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When Uranus, the seventh planet from the Sun, was discovered in 1781, it expanded the known limits of our solar system. It was also the first planet to be discovered using a telescope, as Mercury, Venus, Mars, Jupiter and Saturn were all bright enough to be easily visible to the naked eye.

In fact, because these planets had been known to people for millennia, Uranus was arguably the first planet in recorded history to have been ‘discovered’ at all.

The observations that established Uranus as something other than a regular star were made on 13 March 1781 by Sir William Herschel. He was using a state-of-the-art 2.1-m-long (7-ft) reflecting telescope with a 15.2-cm (6-in) mirror, which he made and installed at his home in Bath, UK. He realized that the point of light known in older star catalogues as "34 Tauri" was in fact something much closer.

He published his findings in a letter to the Royal Society the following month, initially reporting it as a probable comet. Later that year, Anders Johann Lexell (working in St Petersburg, Russia) and Johann Elert Bode (working in Berlin) made follow-up observations that led to the conclusion that the object was in a near-circular orbit, and therefore almost certainly a planet.

Herschel initially suggested calling the new planet Georgium Sidus (George's Star) after the British King, but unsurprisingly this was not a popular choice internationally. Most astronomers called the planet "Herschel" until 1782, when Bode suggested naming the planet after Ouranos, the Greek god of the sky. The name was quickly accepted, although the British government's Nautical Almanac insisted on referring to the planet as Georgium Sidus until 1850.

Credit : Science Museum 

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The Fermi bubbles are two large structures in gamma-rays above and below the Galactic center.  They are associated with the microwave haze around the Galactic center discovered in the WMAP data and recently confirmed in the Planck data.  At the moment, there are several theoretical models and simulations developed to explain the shape and the energy spectrum of the bubbles.  In order to distinguish among the different models, a detailed comparison between the theory and the observations is necessary.  The main purpose of the meeting is to foster a collaboration between the scientists working on the theoretical and observational sides of the problem in order to deepen our understanding of the origin and the emission mechanisms associated with the bubbles.  The topics include: observational results related to the Galactic halo region, models and simulations designed to explain the bubbles, and related systems in other galaxies.

The bubbles may be related to the release of vast amounts of energy emitted from the supermassive black hole at the center of our Milky Way galaxy. We know that in other galaxies, supermassive black holes that ingest large amounts of matter can power high-energy jets. It's possible the Milky Way's central black hole went through such a phase in the past, producing jets responsible for the Fermi Bubbles we see today.

A completely unexpected discovery like the Fermi Bubbles is a special treat. However, scientists know that there are many more surprises waiting to be uncovered by Fermi. In the most recent catalog of sources from Fermi's Large Area Telescope, fully a third of detected source positions are not known to have a gamma-ray emitting object at that location. 

Credit : Space.com

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Putting on a spacesuit takes 45 minutes, including the time it takes to put on the special undergarments that help keep astronauts cool. After putting on the spacesuit, to adapt to the lower pressure maintained in the suit, the astronaut must spend a little more than an hour breathing pure oxygen before going outside the pressurized module.

Initially, it may look like the most expensive item on the space suit is the Primary Life Support System. This unit, which is responsible for adjusting the oxygen and the temperature levels, contains several electronic devices. However, in terms of cost, the parts that NASA spends the most are the gloves of the astronauts. Spacesuit gloves are the main limiting factor when it comes to working in space. Astronauts usually handle from 70 to 110 tools, tethers and associated equipment for a typical spacewalk. Like an inflated balloon, the fingers of the gloves resist the effort to bend them. Astronauts must fight that pressure with every movement of their hand, which is exhausting and sometimes results in injury. Furthermore, the joints of the glove are subject to wear that can lead to life-threatening leaks. For this reason, the gloves are specially designed to aid astronauts' mobility.

In a nutshell, spacesuits are basically wearable spacecrafts and can not only keep astronauts alive, but also feed them, allow them to communicate, and even be used as a toilet.

Credit : Space Camp Turkey

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Armalcolite is a titanium-rich mineral with the chemical formula (Mg,Fe2+)Ti2O5. It was first found at Tranquility Base on the Moon in 1969 during the Apollo 11 mission, and is named for Armstrong, Aldrin and Collins, the three Apollo 11 astronauts. Together with tranquillityite and pyroxferroite, it is one of three new minerals that were discovered on the Moon. Armalcolite was later identified at various locations on Earth and has been synthesized in the laboratory

Armalcolite was originally found on the Moon, in the Sea of Tranquility at Tranquility Base, and also in the Taurus–Littrow valley and the Descartes Highlands. The largest amounts were provided by the Apollo 11 and 17 missions. It was later identified on Earth from samples of lamproite dikes and plugs taken in Smoky Butte, Garfield County, Montana, US. On the Earth, it also occurs in Germany (Nördlinger Ries impact crater in Bavaria), Greenland (Disko Island), Mexico (El Toro cinder cone, San Luis Potosí), South Africa (Jagersfontein, Bultfontein and Dutoitspan kimberlite mines), Spain (Albacete Province and Jumilla, Murcia), Ukraine (Pripyat Swell), United States (Knippa quarry, Uvalde County, Texas and Smoky Butte, Jordan, Montana) and Zimbabwe (Mwenezi District). Armalcolite was also detected in lunar meteorites, such as Dhofar 925 and 960 found in Oman.

Armalcolite is a minor mineral found in titanium-rich basalt rocks, volcanic lava and sometimes granite pegmatite, ultramafic rocks, lamproites and kimberlites. It is associated with various mixed iron-titanium oxides, graphite, analcime, diopside, ilmenite, phlogopite and rutile. It forms elongated crystals up to about 0.1–0.3 mm in length embedded in a basalt matrix. Petrographic analysis suggests that armalcolite is typically formed at low pressures and high temperatures.

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Before there was the International Space Station, before there was Mir, there was Skylab. Established in 1973, and remaining in orbit until 1979, this orbital space station was American's first long-duration orbital workshop, and the ancestor of all those that have followed.

Skylab was launched on May 14th, 1973 on a mission that is sometimes referred to as Skylab 1 (or SL-1). Severe damage was sustained during the launch when the station's meteoroid shield and one of the two solar panels tore off due to vibrations.

Since the station was designed to face the Sun in order to get as much power as possible, and the shield was ripped off, the station rose to a temperature of 52°C. As a result, scientists had to move the space station and effect repairs before astronauts could be dispatched to it.

The first manned mission (designated Skylab 2, or SL-2) took place on May 25th, 1973, atop a Saturn IB and involved extensive repairs to the station. This mission last four weeks, and astronauts Charles Conrad, Jr., Paul J. Weitz, Joseph P. Kerwin were the crew members. During the mission, the crew conducted a number of experiments, including solar astronomy and medical studies, and three EVAs (extra-vehicular activities) were completed as well.

The second manned mission, also known as Skylab 3 (SL-3), was launched on July 28th, 1973. The crew consisted of Alan L. Bean, Jack R. Lousma, and Owen K. Garriott. The mission lasted 59 days and 11 hours, during which time the crew carried out additional repairs as well as performing scientific and medical experiments.

The third and final mission to the Skylab (Skylab 4, SL-4) was the longest, lasting 84 days and one hour. Gerald P. Carr, William R. Pogue, Edward G. Gibson were the crew, and in addition to performing various experiments, they also observed the Comet Kohoutek. The crew conducted three EVAs which lasted a total of 22 hours and 13 minutes.

Skylab was occupied a total of 171 days and orbited the Earth more than 2,476 times during the course of its service. Each Skylab mission set a record for the amount of time astronauts spent in space.

Credit : Phy.org

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Saturn has 82 moons. Fifty-three moons are confirmed and named and another 29 moons are awaiting confirmation of discovery and official naming. Saturn's moons range in size from larger than the planet Mercury — the giant moon Titan — to as small as a sports arena. 

Most of these moons are small, icy bodies that are little more than parts of its impressive ring system. In fact, 34 of the moons that have been named are less than 10 km in diameter while another 14 are 10 to 50 km in diameter. However, some of its inner and outer moons are among the largest and most dramatic in the Solar System, measuring between 250 and 5000 km in diameter and housing some of greatest mysteries in the Solar System.

Saturn’s moons have such a variety of environments between them that you’d be forgiven for wanting to spend an entire mission just looking at its satellites. From the orange and hazy Titan to the icy plumes emanating from Enceladus, studying Saturn’s system gives us plenty of things to think about. Not only that, the moon discoveries keep on coming. As of April 2014, there are 62 known satellites of Saturn (excluding its spectacular rings, of course). Fifty-three of those worlds are named.

Credit : Universe Today

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Saturn is predominantly composed of hydrogen and helium, the two basic gases of the universe. The planet also bears traces of ices containing ammonia, methane, and water. Unlike the rocky terrestrial planets, gas giants such as Saturn lack the layered crust-mantle-core structure, because they formed differently from their rocky siblings.

Saturn is classified as a gas giant because it is almost completely made of gas. Its atmosphere bleeds into its "surface" with little distinction. If a spacecraft attempted to touch down on Saturn, it would never find solid ground. Of course, the craft would be fortunate to survive long before the increasing pressure of the planet crushed it.

Because Saturn lacks a traditional ground, scientists consider the surface of the planet to begin when the pressure exceeds one bar, the approximate pressure at sea level on Earth.

At higher pressures, below the determined surface, hydrogen on Saturn becomes liquid. Traveling inward toward the center of the planet, the increased pressure causes the liquefied gas to become metallic hydrogen. Saturn does not have as much metallic hydrogen as the largest planet, Jupiter, but it does contain more ices. Saturn is also significantly less dense than any other planet in the solar system; in a large enough pool of water, the ringed planet would float.

As on Jupiter, the liquid metallic hydrogen drives the magnetic field of Saturn. Saturn's magnetosphere is smaller than its giant sibling, but still significantly more powerful than those found on the terrestrial planets. With a magnetosphere large enough to contain the entire planet and its rings, Saturn's magnetic field is 578 times as powerful as Earth's.

Credit : Space.com

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Saturn's rings are made of billions of pieces of ice, dust and rocks. Some of these particles are as small as a grain of salt, while others are as big as houses. These chucks of rock and ice are thought to be pieces of comets, asteroids or even moons which were torn apart by the strong gravity of Saturn before they could reach the planet.

Galileo Galilei was the first to see Saturn's rings in 1610, although from his telescope the rings looked more like handles or arms. Forty five years later, in 1655, Dutch astronomer Christiaan Huygens, who had a more powerful telescope, later proposed that Saturn had a thin, flat ring.

As scientists developed better instruments, they continued to learn more about the structure and composition of the rings. Saturn actually has many rings made of billions of particles of ice and rock, ranging in size from a grain of sugar to the size of a house. The particles are believed to be debris left over from comets, asteroids or shattered moons. A 2016 study also suggested the rings may be the carcasses of dwarf planets.

The largest ring spans 7,000 times the diameter of the planet. The main rings are typically only about 30 feet (9 meters) thick, but the Cassini-Huygens spacecraft revealed vertical formations in some of the rings, with particles piling up in bumps and ridges more than 2 miles (3 km) high.

The rings are named alphabetically in the order they were discovered. The main rings, working out from the planet, are known as C, B and A. The innermost is the extremely faint D ring, while the outermost to date, revealed in 2009, is so big that it could fit a billion Earths within it. The Cassini Division, a gap some 2,920 miles (4,700 km) wide, separates rings B and A.

Credit : Space.com

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If humans were to set up home on another planet, scientists say. Mars is our best bet. The interest in sending humans to Mars has never been greater, as many space agencies-private and government-funded - are developing their own human spaceflight to Mars. The U.S. space agency NASA is developing the capabilities needed to send humans to the Red Planet in the 2030s. While Russia plans to send humans in the 2040s, China hopes to do so by 2033. The UAE. a new entrant to space exploration, plans to put a human settlement on Mars within the next 100 years. Mars One and SpaceX also have their eyes set on Mars in the coming decades.

But the question is ‘What is it like to live on Mars?’ To answer that scientists have been recreating Mars-like habitats on Earth! Called Mars analogue habitats, they help prepare astronauts, engineers, and researchers for the future challenges of sending a crewed mission to the Red Planet

NASA has recently set up similar facilities called CHAPEA (short for Crew Health and Performance Exploration Analog) inside its Johnson Space Center in Houston and has invited volunteers with certain qualifications to become crew members at these habitats. What's CHAPEA? What's its purpose?

CHAPEA is a series of analogue missions that will simulate year-long stays on the surface of Mars. Each mission will consist of four crew members living in Mars Dune Alpha, an isolated 1.700 square foot habitat. According to the NASA website, the 3D printed habitat will include private crew quarters, a kitchen, and dedicated areas for medical, recreation, fitness, work, and crop growth activities, as well as a technical work area and two bathrooms. Such a 3D-printed home has been prefered because it is likely that future habitats used during space exploration on Mars will be 3D-printed to prevent the need for launching large, heavy building materials.

What will the CHAPEA crew members do?

During the mission, the crew will conduct simulated spacewalks and provide data on a variety of factors, which may include physical and behavioural health and performance. They will consume ready-to-eat space food and will try to grow plants. The paid volunteers will try to survive with limited communications back home, restricted resources and equipment failures. Exercising, hygiene activities, maintenance work and science work are some of the other activities planned for the volunteers.

What is the purpose of this analogue?

Researchers will analyse the social and teamwork dynamics of the crew. The programme will be critical in understanding how trained individuals will perform under the rigours and pressures of a Mars mission.

Specifically, it will not only highlight operational challenges, but will also illuminate the physical and mental health challenges that future astronauts may encounter in long-duration space missions.

When will the project begin?

NASA is planning three of these experiments with the first one starting in the fall next year (September 2022).

Where were some of the past Mars analogue habitats located?

• The Mars Society, a space advocacy group established the Flashline Mars Arctic Research Station (FMARS) in 2000 in the territory of Nunavut, Canada. FMARS Crew 11 remained in the Martian simulation for 100 days.
• It set up its second habitat in Utah, whose crew members focussed on conducting field research in simulated Martian conditions.
• The Mars-500 mission was a series of experiments conducted between 2007 and 2011 and sponsored by Russia, the European Space Agency, and China. Unlike other Mars Analog missions, Mars-500 did not take place in a Mars-like environment, but in a Moscow research institute. An important focus of the Mars-500 research was the diagnosis of "adverse personal dynamics” which would affect cooperation among the crew.

How I can humans live on Mars, if they were to settle there?

Compared to other planets, Mars has its advantages when it comes to human habitation. It is the closest planet to Earth. Its soil contains water and there is enough sunlight to use solar panels Human body can adapt to the gravity on Mars, which is 38% that of Earth's, and day-length in Mars is similar to that of Earth. However, humans cannot live on Mars like they do on Earth

 

Mars has no oxygen in its atmosphere and it is very cold on its surface - the average temperature of Earth is about 50 degrees Fahrenheit, while the average temperature on Mars is minus 100 degrees Fahrenheit. There's also virtually no air pressure. Mars temperature variations often result in powerful dust storms. Though these storms probably wouldn't physically harm us, the dust could dog electronics and interfere with solar powered instruments.

So, to survive on Mars, humans will need special equipment and pressurised and heated habitats. The habitats are to be self-sustaining sealed against the thin atmosphere, and capable of supporting life for extended periods of time. Humans will also need a spacesuit whenever they go outside the habitat. Despite wearing a suit, radiation from space could ham the human settlers.

For a longer stay, humans will have to figure out how to extract water from underground supplies, and how to produce their own food Scientists believe that we could sustain life there by producing food under artificial light and growing genetically modified plants Space companies are already designing prototypes of habitation humans will need to survive on Mars.

Here are some of the basic facts that astronomers have learnt about the planet over the years.

• Mars, the fourth planet from the Sun in the Solar System, is an icy desert. It has two moons Phobos and Deimos.
• It is half the size of Earth, and gets its name the Red Planet because iron minerals in its soil oxidise or rust thereby making its surface and atmosphere look red.
• One Martian year is 687 Earth days.
• Mars has seasons and weather patterns. It has polar ice caps, canyons and even dead volcanoes. It has a very thin atmospheric layer.
• Mars, at the farthest point of its orbit, is about 400 million kilometres, from Earth, and 55 million kilometres at the nearest point.

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Earth is the only planet not named after a Roman god or goddess, but it is associated with the goddess Terra Mater (Gaea to the Greeks). In mythology, she was the first goddess on Earth and the mother of Uranus. 

 The name Earth comes from Old English and Germanic. It is derived from “eor(th)e” and “ertha,” which mean “ground.” Other civilizations all over the world also developed terms for our planet.

Mars is named after the Roman god of war. The planet got its name from the fact that it is the color of blood.  Other civilizations also named the planets for its red color.

Jupiter was the Roman king of the gods. Considering that Jupiter is the largest planet in our Solar System, it makes sense that the planet was named after the most important god.

Saturn was named after the Roman god of agriculture and harvest. While the planet may have gotten its name from its golden color, like a field of wheat, it also had to do with its position in the sky. According to mythology, the god Saturn stole the position of king of the gods from his father Uranus. The throne was then stolen by Jupiter.

Uranus was not discovered until the 1800’s, but the astronomers in that time period continued the tradition of naming planets after Roman gods. In mythology, Uranus was the father of Saturn and was at one time the king of the gods.

While Neptune almost ended up being named after one of the astronomers credited with discovering it – Verrier – that was greatly disputed, so it was named after the god of the sea. The name was probably inspired by its blue color.

Pluto is no longer a planet, but it used to be. The dark, cold, former planet was named after the god of the underworld. The first two letters of Pluto are also the initials of the man who predicted its existence, Percival Lowell.

Credit : Universetoday.com

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Phobos and Deimos bear more resemblance to asteroids than to Earth's moon. Both are tiny — the larger, Phobos, is only 14 miles across (22 kilometers), while the smaller, Deimos, is only 8 miles (13 km), making them some of the smallest moons in the solar system.

Both are also made up of material that resembles Type I or II carbonaceous chondrites, the substance that makes up asteroids. With their elongated shapes, they even look more like asteroids than moons.

Even from Mars, the moons don't look like moons. The more distant moon, Deimos, appears more like a star in the night sky. When it is full and shining at its brightest, it resembles Venus as seen on Earth. Phobos has the closest orbit to its primary of any moon in the solar system, but still only appears a third as wide as Earth's full moon.

Phobos orbits only 3,700 miles (6,000 km) from the Martian ground. Its surface is marred by debris that may have come from impacts on Mars. It travels around the planet three times a day, zipping across the Martian sky approximately once every four hours. The fast-flying moon appears to travel from west to east.

Deimos orbits much farther away, tending to stay 12,470 miles (20,069 km) from the red planet's surface. The moon takes about 30 hours, a little over a Martian day, to travel around its host.

Credit : Space.com

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Experts have suggested the actual boundary between Earth and space lies anywhere from a mere 18.5 miles (30km) above the surface to more than a million miles (1.6 million km) away. However, for well over half a century, most — including regulatory bodies — have accepted something close to our current definition of the Kármán Line.

The Kármán line is based on physical reality in the sense that it roughly marks the altitude where traditional aircraft can no longer effectively fly. Anything traveling above the Kármán line needs a propulsion system that doesn’t rely on lift generated by Earth’s atmosphere — the air is simply too thin that high up. In other words, the Kármán line is where the physical laws governing a craft's ability to fly shift. 

However, the Kármán line is also where the human laws governing aircraft and spacecraft diverge. There are no national borders that extend to outer space; it’s governed more like international waters. So, settling on a boundary for space is about much more than the semantics of who gets to be called an astronaut.

The United Nations has historically accepted the Kármán line as the boundary of space. And while the U.S. government has been reticent to agree to a specific height, people who fly above an altitude of 60 miles (100 km) typically earn astronaut wings from the Federal Aviation Administration. Even the Ansari X-prize chose the Kármán line as the benchmark height required to win its $10 million prize, which was claimed when Burt Rutan’s SpaceShipOne became the first privately-built spacecraft to carry a crew back in 2004.

Credit : Astronomy.com

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The average temperature of outer space around the Earth is a balmy 283.32 kelvins (10.17 degrees Celsius or 50.3 degrees Fahrenheit). This is obviously a far cry from more distant space's 3 kelvins above absolute zero. But this relatively mild average masks unbelievably extreme temperature swings. Just past Earth's upper atmosphere, the number of gas molecules drops precipitously to nearly zero, as does pressure. This means there is almost no matter to transfer energy -- but also no matter to buffer direct radiation streaming from the sun. This solar radiation heats the space near Earth to 393.15 kelvins (120 degrees Celsius or 248 degrees Fahrenheit) or higher, while shaded objects plummet to temperatures lower than 173.5 kelvins (minus 100 degrees Celsius or minus 148 degrees Fahrenheit).

The key defining characteristic of outer space is emptiness. Matter in space concentrates into astronomical bodies. The space between these bodies is truly empty -- a near-vacuum where individual atoms may be many miles apart. Heat is the transfer of energy from atom to atom. Under outer space conditions, almost no energy is transferred because of the vast distances involved. The average temperature of empty space between celestial bodies is calculated at 3 kelvins (minus 270.15 degrees Celsius or minus 457.87 degrees Fahrenheit). Absolute zero, the temperature at which absolutely all activity stops, is zero kelvins (minus 273.15 degrees Celsius or minus 459.67 degrees Fahrenheit).

Distance from stars determines the average temperature of specific points in space. Whether a specific point is fully exposed to light or partially or fully shaded determines its temperature at a specific time. Distance and light exposure are the prime temperature determinants for all objects and points that lack atmosphere and are suspended in near-vacuum.

Credit : Sciencing

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