My Science School

The largest planet in the solar system, the gas giant Jupiter is approximately 318 times as massive as Earth. If the mass of all of the other planets in the solar system were combined into one "super planet," Jupiter would still be two and a half times as large.

Jupiter has a mean radius of 43,440.7 miles (69,911 kilometers), about a tenth that of the sun. However, its rapid rotation — it spins once every 9.8 hours — causes it to bulge at the equator, where the diameter is 88,846 miles (142,984 km). In contrast, the diameter at the poles is only 83,082 miles (133,708 km). This stretched shape is known as an oblate spheroid.

If you were to walk around the equator of Jupiter, you would travel 272,946 miles (439,264 km), over 10 times the distance around Earth's center line.

Because Jupiter is made of gas, mostly, its surface is considered uniform. As such, it lacks high and low points — mountains and valleys — such as those found on rocky terrestrial planets.

Credit : Space.com

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What’s the closest planet to our own? Common sense would say the answer is either Mars or Venus, our next door neighbors. Of the two, Venus comes closer to the Earth than any other planet and its orbit is closest to ours. But as an article in Physics Today points out, over half the time Venus is not the nearest planet; Mercury is. In fact, the scientists behind the article crunched the numbers and found that on average, Mercury is the closest planet not only to Earth but to every other planet in the solar system as well.

The scientists developed a simulation of our solar system featuring all of the planets moving in their orbits. They let the planets orbit for thousands of simulated years, all the while calculating the distance between any two of them. The scientists then averaged those values together to find which planets are the closest to each other over time.

Surprisingly, they found that Mercury was the closest planet to all seven other planets. This might seem impossible, but it makes sense if you realize that every planet spends about half its time on the opposite side of the Sun. In Earth’s case, while Venus does get very close to Earth it also spends plenty of time very, very far away.

This is a very different way to calculate the ‘closest planet’ than most people use; typically, the distance from one planet to another is taken to mean the distance between the two planets’ orbits. But this result shows there’s more than one way to define our closest neighbor.

Credit : Physics Today 

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The heaviest artificial objects to reach space include space stations, various upper stages, and discarded Space Shuttle external tanks. Spacecraft may change mass over time such as by use of propellant.

Currently the heaviest spacecraft is the International Space Station, nearly double Shuttle-Mir's mass in orbit. It began assembly with a first launch in 1998, however it only attained its full weight in the 2020s, due to its modular nature and gradual additions. Its mass can change significantly depending on what modules are added or removed.

The ISS was originally intended to be a laboratory, observatory, and factory while providing transportation, maintenance, and a low Earth orbit staging base for possible future missions to the Moon, Mars, and asteroids. However, not all of the uses envisioned in the initial memorandum of understanding between NASA and Roscosmos have been realised. In the 2010 United States National Space Policy, the ISS was given additional roles of serving commercial, diplomatic, and educational purposes.

The ISS provides a platform to conduct scientific research, with power, data, cooling, and crew available to support experiments. Small uncrewed spacecraft can also provide platforms for experiments, especially those involving zero gravity and exposure to space, but space stations offer a long-term environment where studies can be performed potentially for decades, combined with ready access by human researchers.

The ISS simplifies individual experiments by allowing groups of experiments to share the same launches and crew time. Research is conducted in a wide variety of fields, including astrobiology, astronomy, physical sciences, materials science, space weather, meteorology, and human research including space medicine and the life sciences. Scientists on Earth have timely access to the data and can suggest experimental modifications to the crew. If follow-on experiments are necessary, the routinely scheduled launches of resupply craft allows new hardware to be launched with relative ease. Crews fly expeditions of several months' duration, providing approximately 160 person-hours per week of labour with a crew of six. However, a considerable amount of crew time is taken up by station maintenance.

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Olympus Mons is the largest volcano in the solar system. The massive Martian mountain towers high above the surrounding plains of the red planet, and may be biding its time until the next eruption.

Found in the Tharsis Montes region near the Martian equator, Olympus Mons is one of a dozen large volcanoes, many of which are ten to a hundred times taller than their terrestrial counterparts. The tallest of them all towers 16 miles (25 kilometers) above the surrounding plains and stretches across 374 miles (624 km) — roughly the size of the state of Arizona.

In comparison, Hawaii's Mauna Loa, the tallest volcano on Earth, rises 6.3 miles (10 km) above the sea floor (but its peak is only 2.6 miles above sea level). The volume contained by Olympus Mons is about a hundred times that of Mauna Loa, and the Hawaiian island chain that houses the Earthly volcano could fit inside its Martian counterpart.

Olympus Mons rises three times higher than Earth's highest mountain, Mount Everest, whose peak is 5.5 miles above sea level. 

Credit : Space.com

Picture Credit : Google

It depends on which part of the space we are talking about. In general, it works like this: the closer to the stars, the higher the temperature. Another factor that weighs is the presence of matter: heat can be retained by it. As space becomes empty, temperature drops. In a vacuum (absence of matter), the temperature drops to 2.7 Kelvin or -270.45 Celsius. Only a few degrees above absolute zero (-273.15 °C).

There is no place colder than space. It has a lot of empty regions distant from heated bodies. The lowest temperature ever recorded on Earth was -89.2 ºC, in Antarctica. In interstellar space, where there is no absolute void (there are gases and dust grains), the temperature varies.

At the Earth’s thermosphere, where the atmosphere turns into space, the exact temperature can also vary substantially. However, the average temperature above 300 km is about 427 degrees Celsius at solar minimum and 927 degrees Celsius at solar maximum. But this does not mean that the space above the atmosphere is at this temperature. In fact, it is very cold. Only a body in this region that is illuminated by the sun can reach this temperature. In the dark areas of space, temperatures would drop a lot.

On the Moon, which has no atmosphere, temperatures vary a lot. When sunlight reaches the moon’s surface, the temperature can reach 127 degrees Celsius. However, when the sun goes down, temperatures can drop to – 173 degrees Celsius.

Credit : Curiosity Guide 

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From the depths of the ocean floor to the freezing glaciers of the Antarctica, you may have heard of films being shot in the most extreme locations on the planet. And now for the first time, a Russian film crew-racing ahead of Hollywood-is attempting to shoot a feature film in space, aboard the actual International Space Station, which orbits the Earth at about 400 km above its surface.

A Russian cosmonaut Anton Shkaplerov along with the film crew actor Yulia Peresild and film producer Klim Shipenko rocketed to space on October 5 aboard Russia's MS-19 Soyuz spacecraft to shoot what might become the first feature film in t orbit.

History in the making

While space has often been portrayed on the silver screen using advanced computer graphics, there has never been a full-length film shot and directed in space. Hence, the mission if successful will truly become an important landmark in cinematic history.

What it's about

The film named "The Challenge" is about a surgeon, played by Peresild, who goes on an emergency mission to the space station to treat an injured cosmonaut.

Since the crew has to travel light they are not carrying any heavy cameras and equipment Instead, the scenes will be shot using hand-held cameras. The film will include about 35 to 40 minutes of scenes made on the station.

The crew has only two weeks to complete shooting the film, before making their return to Earth on October 17. Obviously, once the shoot wraps up, there will be no retakes!

The space race

During the Cold War, the US and the then Soviet Union were caught in a space race, with both the countries wanting to be the first to make forays into space. In 1957, the Soviet Union beat the US by sending Laika the dog aboard Sputnik 2. Laika became the first living creature to be shot into space and orbit Earth

Similarly Russia's Yuri Gagarin became the first kuuman to rocket into the Earthy orbit just a few days before American Alan Shepard. And with the latest space film mission, the space race seems to have taken a cinematic turn.

In 2020, it was reported that Hollywood megastar Tom Cruise plans to fly to space aboard one of Spacers Crew Dragon capsules for an action-adventure film directed by Doug Liman However, it is unclear when this will happen.

Space tourism

A few years back, it was unimaginable for anyone but a trained astronaut to travel to space. However, over the year concerted efforts are being made to promote space tourism. In July 2021, the nearly 71-year-old Richard Branson and five crewmates from his space-tourism company Virgin Galactic flew to an altitude of about 88 km over the New Mexico desert. They experienced three to four minutes of weightlessness and saw the curvature of the Earth before making a safe landing. Not to be left behind, few days later, billionaire Jeff Bezos too made a quick sojourn to space on his rocket ship, New Shepard. His company, Blue Origin plans to carry William Shatner, who played Captain Kirk in the popular "Star Trek" series on October 12.

Did you know?

Some of the films shot in space:

• In 2008, Richard Gamott, a private astronaut shot a short sci-film in space named "Apogee of Fear The film was only eight minutes long. Garriott paid $30 million to travel on the Soyuz spacecraft
• In 2002, IMAX productions used videos shot aboard the space station in its documentary "Space Station 3D".

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The farther you get away from the Sun, the cooler you get. So let’s take a look at those planets that sit between Earth and the Sun: Mercury and Venus.

Since Mercury sits closest to the Sun, it must be the hottest planet. Right? That only makes sense, doesn’t it? After all, Mercury receives more sunlight per square foot than any other planet in the solar system. Wrong! Venus is actually the hottest planet in the solar system.

On a hot day on Mercury, the temperature can rise to over 700 ºF. That’s hot! You’d definitely need plenty of sunscreen there. A hot day on Venus, however, is even hotter. How much so? The highest temperatures on Venus exceed 900 ºF. Yikes! Now that’s a scorcher, for sure.

Most friends are probably wondering why Venus is hotter than Mercury. After all, it’s farther away from the Sun. The answer lies in the atmosphere. 

Mercury is small and sits closest to the Sun. It also moves very quickly around the Sun. For these reasons, it doesn’t have an atmosphere. When the Sun’s rays hit Mercury, they just bounce off into space. There’s nothing to reflect them back toward the planet and retain their heat.

Venus, on the other hand, has a very thick atmosphere. Its atmosphere is actually over 90 times denser than Earth’s atmosphere. It’s also made up mostly of carbon dioxide, a greenhouse gas. Venus’s atmosphere acts like a one-way door. It lets in solar radiation, but it doesn’t let it back out.

This creates oven-like conditions on the surface of Venus. Because of this intense heat, no water can be found there. Moreover, carbon dioxide is a noxious gas. It creates raging winds that blow constantly across the surface of the planet. This gives it one of the harshest environments you’re likely to find in the entire solar system. Earth and Venus are sometimes called “sister” planets because of their similar sizes. But in most other ways, they couldn’t be more different.

Before scientists could see Venus with the help of unmanned probes and space telescopes, many of them thought Venus was a lush, tropical paradise. The truth is that it’s a barren rock that looks like Earth’s Moon. Its clouds appear yellowish because of the presence of sulfur dioxide alongside the huge amounts of carbon dioxide.

Credit : Wonderopolis 

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Polaris, known as the North Star, sits more or less directly above Earth's north pole along our planet's rotational axis. This is the imaginary line that extends through the planet and out of the north and south poles. Earth rotates around this line, like a spinning top.

Polaris is located quite close to the point in the sky where the north rotational axis points – a spot called the north celestial pole. As our planet rotates through the night, the stars around the pole appear to rotate around the sky. Over the hours, these stars each sweep out a circle around the celestial pole. The farther a star is from the pole, the larger the circle it travels around the sky. Some stars travel a great distance over the course of the night.

Polaris is different. Because it's so close to the celestial pole, it traces out a very small circle over 24 hours. So Polaris always stays in roughly the same place in the sky, and therefore it's a reliable way to find the direction of north. It would appear directly overhead if you stood at the north pole, but farther south, it indicated the direction of north.

One other note about the North Star is that it's a title that passes to different stars over time. Earth's axis of rotation wobbles over the course of about 26,000 years, the way a spinning top also wobbles as it spins. This causes the celestial pole to wander in a slow circle over the eons, sweeping past different stars. Sometimes there's no bright star near the celestial pole, as is the case in the Southern Hemisphere at present. About 14,000 years ago, the celestial pole pointed toward the bright star Vega, and as it sweeps out its slow circle, it will again point to Vega in about 12,000 years.

Credit : NASA Science 

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Just to be clear, this answer to ‘which planet has the longest day’ is based on this criteria: a planets day is how long it takes it to complete one rotation on its axis. This is also referred to as its rotational period. So, Venus has the longest day of any planet in our solar system. It completes one rotation every 243 Earth days. Its day lasts longer than its orbit. It orbits the Sun every 224.65 Earth days, so a day is nearly 20 Earth days longer than its year.

Now, back to why the Venusian day is longer than its year. Venus is closer to the Sun; therefore, its orbit takes a shorter period of time than its rotation upon its axis. The planet also rotates in retrograde. That means it spins in the opposite direction of the Earth. If you were standing on Venus, you could see the Sun rise in the West and set in the East.

A manned Venus flyby mission was proposed in the late 1960s. The mission was planned to launch in late October or early November 1973, and would have used a Saturn V rocket to send three men. The flight would have lasted approximately one year. The spacecraft would have passed approximately 5,000 km from the surface about four months into the flight. There have been several unmanned probes and flybys of the planet, including MESSENGER and the Venus Express. Future proposed missions include the BepiColombo, Venus InSitu Explorer, and the Venera-D.

Credit : Universe Today 

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The earth has about 70 percent of water on its crust. It also has an abundance of oxygen thanks to its multilayered atmosphere made of several gasses. The moon neither has oxygen nor water. It weak atmosphere does not support the formation of oxygen. Hence it remains a barren and lifeless astral body. However, the possibilities of finding water and ice on the moon are being explored by humans through several studies now.

The moon has only a very thin atmosphere, so a layer of dust — or a footprint — can sit undisturbed for centuries. And without much of an atmosphere, heat is not held near the surface, so temperatures vary wildly. Daytime temperatures on the sunny side of the moon reach 273 degrees F (134 Celsius); on the night side it gets as cold as minus 243 F (minus 153 C).

The moon's gravity pulls at the Earth, causing predictable rises and falls in sea levels known as tides. To a much smaller extent, tides also occur in lakes, the atmosphere and within Earth's crust.

High tides refer to water bulging up from Earth's surface, and low tides when water levels drop. High tides occur on the side of the Earth nearest the moon due to gravity, and on the side farthest from the moon due to the inertia of water. Low tides occur between these two humps.

The pull of the moon is also slowing the Earth's rotation, an effect known as tidal braking, which increases the length of our day by 2.3 milliseconds per century. The energy that Earth loses is picked up by the moon, increasing its distance from the Earth, which means the moon gets farther away by 1.5 inches (3.8 centimeters) annually.

Credit : Space.com 

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The speed of light is approximately 1,079,000,000 kilometers/hour (670,600,000 miles/hour). On average, the Sun is 150 million kilometers (93 million miles) away from Earth. This means that it takes a photon of light about 8 minutes and 20 seconds to travel from the Sun to Earth.

Objects in our universe are extremely far away. They’re so far away that kilometers or miles aren’t a useful measure of their distance. So we speak of space objects in terms of light-years, the distance light travels in a year. Light is the fastest-moving stuff in our universe. It travels at 186,000 miles per second (300,000 km/sec). And thus a light-year is 5.88 trillion miles (9.46 trillion kilometers).

But stars and nebulae – not to mention distant galaxies – are vastly farther than one light-year away. And, if we try to express a star’s distance in miles or kilometers, we soon end up with impossibly huge numbers. Yet miles and kilometers are what most of us use to comprehend the distance from one place on Earth to another. In the late 20th century astronomer Robert Burnham, Jr. – author of Burnham’s Celestial Handbook – devised an ingenious way to portray the distance of light-years in terms of miles and kilometers.

Credit : Earth Sky

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In December 2018, NASA's Voyager 2 spacecraft reached interstellar space, following the example of its sister, Voyager 1. Right now, only five spacecraft have been launched capable of making such a grand exit, including the Voyagers. The remaining three are Pioneers 10 and 11, and New Horizons.

This milestone — reaching interstellar space — can be considered leaving the solar system by a certain definition. Let's be clear about what that entails. In 1990, the New York Times reported that Pioneer was reported to leave the solar system when it flew past Neptune's orbit. That's not what Voyager 2's scientists used to make their determination, however. Instead, the more recent measurements consider the crossing of the sun's heliopause, the theoretical boundary to its heliosphere, to be the determining factor for entering interstellar space. The heliosphere is a bubble of charged particles created by and flowing past the sun. Scientists use it to mark where interstellar space begins. 

But the heliosphere is tricky, and changes along with the sun's 22-year solar cycle, shrinking and growing with the solar wind, and stretching out behind the sun in the star's direction of travel. It's not something easily measured from Earth. NASA's Interstellar Boundary Explorer (IBEX) mission is working to remotely define the edges of the bubble.

Credit : Space.com

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The carbonaceous asteroids are abundant in the solar system (almost 75% of the known asteroids are of this type), especially on the edge of the asteroid belt between Mars and Jupiter (some astronomers say that another planet could have formed in that asteroid belt if Jupiter’s gravity wasn’t so massive, but now a possible planet lies in pieces in between Mars and Jupiter). 

As their name suggests, they are rich in carbon among other silicates and metals and are thus dark, which is why we might not have detected many more asteroids of this type in the outer reaches of our solar system. 

After the C-type asteroids, we have the S-type asteroids made of silicate and iron-nickel to be the next most abundant group in our system. They are very common on the inner edge of the asteroid belt and contribute 17% of the total asteroids in the entire system. 

With an albedo of 0.2, they are fairly bright and easier to see when we compare them to C-type asteroids. The largest in this group is 15 Eunomia at 205 miles or 330 km across that makes up 1% of the asteroid belt’s mass.

While the M-type asteroids are the third most common asteroid group, we don’t know much about their composition. They are located in the middle of the asteroid belt, and most if not all contain nickel and iron, but the subtler compositional characteristics depend on their distance from the Sun. 

Those close to it melted partially and basaltic lava oozed out onto the surface while those away from the Sun were able to hold on to their composition and structure.

The most massive asteroid in this group is the 16 Psyche with a diameter of 120 miles or 200 km.

Credit : Starlust

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