Category Archives: Planets

What Do You Know about Saturn’s Rings?

Saturn's Rings
The attenuation of 0.94-, 3.6-, and 13-centimeter signals sent by Cassini through the rings to Earth shows abundance of particles in the rings of Saturn

Our universe is full of surprises and it’s an absolutely divine work of art. There’s a lot we, the petty humans have already discovered about this grand realm – and one out of that overflowing trove of information is the fact that Saturn has rings surrounding its circumference.

Now how is that fair? Earth gets water and Saturn gets RINGS!

Not that we’re not grateful for the water, but if Earth wanted rings too just what could it do to get those?

Here’s all you need to know about the Saturn Rings:

It was Galileo Galilei, the famous Italian astronomer who first discovered the Saturn Rings back in 1610 – he thought they resembled arms or handles! Unfortunately, Galilei’s telescope wasn’t powerful enough to figure out what they were exactly. Enter comes Christiaan Huygens – the Dutch astronomer who declared that they were actually a flat, thin ring.

Later, with the advent of more powerful telescopes it became evident that Saturn wasn’t just surrounded by one thin, flat ring. In fact, there were many. The largest one out of those was estimated to be around two hundred times the size of the planet’s own diameter which is approximately, 116,464 kilometers. 

These rings are alphabetically in the order of their discovery. Most of these rings are generally not more than thirty feet in thickness. There are four core rings that work out from the planet itself. They are named D, C, B, and A. The innermost ring D is the faintest and the outermost is big enough to house a billion Earths! No, we’re not kidding.

Most of the fainter rings were discovered with the improvement in the telescopes with technological advances. It was Voyager 1 – the NASA space probe launched in 1977 that discovered the Ring D back in 1980. After Ring A is the Ring F, followed by ring G and E.

The rings are separated by gaps and structures. While some gaps are justified by the presence of the smaller moons of Saturn, others still have the astronomers confused. These rings are all typically quite close to each other; however the rings B and A are separated by the Cassini Division – a span of 4,700 kilometers.

Did you know that Saturn is not the only planet with rings? Neptune, Uranus, Jupiter also have rings! However, their rings aren’t so much visible because they do not have the moon span of 282,000 kilometers.

So what exactly are these rings made of?

Astronomers and scientists reveal that the rings surrounding Saturn are made up of particles. These particles range in size – some as small as grain and others as big as the size of the mountains. Most of these particles are made of ice – yes water-ice!

It is the rings that draw in particles floating in outer space and at times these particles are rocky meteoroids too.

Still wondering if rings composed of ice particles amount to the presence of water on and/or around the planet. What do you think?

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The Ringed Gas Giant: Saturn

Saturn Compared to Earth

Although all four gas giant planets have rings made of ice and rocks, Saturn has the most spectacular rings. There are seven rings in total and the largest ring is up to 200 times the planet’s diameter. However, although the rings extend thousands of miles from the planet, they are only about 30 feet thick.

One day on Saturn last 10.7 hours and it takes the planet 29 Earth years to orbit the Sun. It is the farthest planet from the Sun that can be seen with the naked eye.

Saturn is a gas giant made up of mostly hydrogen and helium and does not have a solid surface. Although Saturn cannot sustain any life, some of its 62 moons might be able to support life. Most of the moons are named after Titans in Greek mythology because Saturn itself is named after Cronus, the lord of the Titans.

Saturn’s moons are all very different. Titan is the largest of Saturn’s moons and is slightly larger than Mercury. Pan and Atlas are shaped like flying saucers. One half of Iapetus is bright like snow while the other half is dark. Enceladus as 101 geysers at the southern pole that spew water and other chemicals. And others like Prometheus and Pandora interact with the rings to keep them in their orbits.

In 1979, Pioneer 11 was the first spacecraft to reach Saturn and flew within 13,700 miles of it. In doing so, it discovered the planet’s two outermost rings. The Cassini spacecraft is currently in orbit around Saturn and has returned incredible data on the planet and its moons over the last decade of observation.

The Reality of a Mission to Mars

The summer of 2015 may have belonged to Pluto, but it looks like Mars has taken the spotlight this fall. First, scientists announced evidence of liquid water flows on Mars, and then the movie The Martian was released in theaters.

In late September 2015, the NASA Mars Reconnaissance Orbiter’s imaging spectrometer detected signatures of hydrated minerals on slopes. The streaks appear to ebb and flow, and flow down steep slopes during warm seasons.

The flows are possibly related to liquid water.

“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate in Washington, said in a statement. “This is a significant development, as it appears to confirm that water—albeit briny—is flowing today on the surface of Mars.”

The darkened streaks on the Red Planet’s surface were first discovered in 2010 by University of Arizona undergraduate student Lujendra Ojha, now of the Georgia Institute of Technology.

“When most people talk about water on Mars, they’re usually talking about ancient water or frozen water,” he said. “Now we know there’s more to the story.”

So does the presence of liquid mean Mars could support life? In the movie The Martian, based on the book of the same title, astronauts in 2030 are making fairly regular trips to Mars to live for months at a time and study the planet and its ability to sustain life more closely. And, in fact, NASA has proposed sending manned spacecraft to Mars by 2030—a feat that won’t be easy.

As the movie shows, the trip to Mars will take a long time—8 months—and that long voyage under zero gravity will have adverse effects, such as bone density and muscle loss. In addition, another issue the movie addresses, the Mars team will not be able to easily communicate with home. At the distance they will be from Earth, there will be a long lag for radio signals and communication will take at least 7 minutes.

Combine those challenges with cold temperatures, a thin atmosphere, huge dust storms, and potentially harmful ultraviolet radiation from the sun, and a mission to Mars may almost seem impossible. But it’s possible NASA will be able to work around some of the problems.

“As the astronauts establish their base, NASA is planning to use Mars’ own resources to overcome some of these obstacles,” Sidney Perkowtiz, PhD, MS, Emeritus Candler Professor of Physics at Emory University, wrote in a blog post for the university.

The new discovery of surface water means NASA astronauts won’t have to mine for water below the Martian surface, plus oxygen is readily abundant in the atmospheric CO2, which can be broken up into breathable oxygen. And it is possible that Martian sources can be used to produce compound methane to be used as rocket fuel for the return trip, according to Dr. Perkowitz.

What might make the premise of The Martian seem more realistic than anything else is the fact that 9 of the technologies in the movie that make habitation on the planet possible for the fictional astronauts are very much real.

For instance, just as Matt Damon’s character grows plants in a created farming space, recently astronauts were successfully able to grow lettuce in the International Space Station.

“Every extra pound that has to be hauled up from Earth makes the project that much more difficult,” Dr. Perkowitz explained. “‘Living off the land’ on Mars, though it might affect the local environment, would hugely improve the odds for success of the initial mission—and for eventual settlements there.”

In addition, the habitation module in the movie has a real-world equivalent in the Human Exploration Research Analog, a self-contained environment that real-life crews use to train for long-duration space missions.

Plus, NASA also has prototype space exploration suits and a Multi-Mission Space Exploration Vehicle, which will allow for long travel on other planets.

“Yes, we’re closer to Mars than many may think,” Dr. Perkowitz wrote. “And a successful manned mission could be the signature human achievement of our century.”

Potential Life Sustaining Planets are Closer and Closer

With the new Star Wars films getting science fiction fans excited, there is another reason to why science lovers should also be getting excited. A super-Earth type planet has been spotted by Australian astronomers and it’s only 14 light years away.

Back in 2013, a team of astronomers led by Dr. Duncan Wright from the University of New South Wales, discovered the planet similar to earth using the HARPS spectrograph, part of the European Southern Observatory’s telescope in La Salla in Chile. This solar system contains the inactive red dwarf star known as Wolf 1061which is orbited by possibly seven planets, including three super-Earths. These planets that may be capable of supporting life. as they have a low enough mass to be potentially rocky with a solid surface.

The most interesting of the three planets is the one dubbed Wolf 1061c. At 4 times the size of our Earth, it is the closest possibly habitable planet outside our solar system. It also sits in the “Goldilocks Zone“, close enough to its sun to contain liquid water and support life with its mild temperatures.

habitable-zone diagram

Even though small rocky planets similar to our own as well as multi-planet systems are known to be abundant in our galaxy, most of the ones discovered are hundreds if not thousands of light years away. They are too far for us to get to using current technology. With the hope of Wolf 1061c sitting right next door, scientists are now hopeful that they can test the planets atmosphere in more detail once it passes across the face of its star, making the not so lone Wolf planet easier to study and determine if it truly has the potential to sustain life.

The Lonely Life of Rogue Planets

While many children are taught that planets orbit a star, the way the Earth and the other planets in our Solar System orbit the Sun, that’s not strictly true. There are planets drifting out in space that are known as rogue planets, or starless planets.

Rogue planets orbit a galaxy after either having been ejected from the planetary system in which they formed or having never been gravitationally bound to any star. Recently, the largest known rogue planet, known as 2MASS J2126, was discovered to have a star after all. The planet orbits 600 billion miles from its host star, which makes its solar system the largest one known, according to Space.com. The planet completes one orbit every 900,000 years or so.

“This is the widest planet system found so far and both the members of it have been known for eight years, but nobody had made the link between the objects before,” Dr. Niall Deacon of the University of Hertfordshire, who lead the team of researchers that discovered the connection, said in a statement. “The planet is not quite as lonely as we first thought, but it’s certainly in a very long distance relationship.”

According to the Royal Astronomical Society, there is unlikely to be aby life on the planet, but if there were, they would see their sun as just a bright star in the sky and probably wouldn’t even know they were connected to it all.

The closest rogue planet to Earth is WISE 0855-0714, which is still roughly 7 light years away. Rogue planets are difficult to be detected since astronomers usually rely on the planet’s orbit around a host star. However, there are 2 other methods of detecting rogue planets: gravitational microlensing and direct imaging.

There are 8 known rogue planets, discovered within the last 6 years. As of yet, there is no way of knowing whether these planets were ejected from orbiting a star or originally formed on their own.

In Cosmos: A Spacetime Odyssey, Neil deGrasse Tyson introduced viewers to the concept of lonely, interstellar planets. Tyson said that the galaxy has billions of these rogue planets. In fact, it’s possible that our own Solar System has cast out a planet that is now drifting along in space. National Geographic reported that most theories describing the early Solar System don’t work unless there had been another fifth giant planet present at the start and that this fifth giant was kicked out of the Solar System.

Strange and Unusual Exoplanets

Although astrophysicists have a vested interest in searching for other Earth-like planets that could support life, the study of space has unearthed some incredibly unique and unexpected exoplanets (planets located beyond our own Solar System). True, there is not likely to be any life found on them, but they are fascinating in their own right because of how unusual they are.

Since exoplanets are located so far outside our own Solar System, astronomers can only detect them as the planets pass directly in front of the star they orbit. When that happens, they block part of the light, which appears as though the star has been momentarily dimmed.

Burning Ice

exoplanet_comparison_tres-3_b
“Exoplanet TrES-3 b with planet Jupiter” width=”1040″ height=”480″ /> Comparison of the exoplanet TrES-3 b with the planet Jupiter (Creative Commons Attribution-Share Alike 3.0 Unported license)

The planet Gliese 436b is located 33.4 light-years away and has been called the planet of burning ice or the “hot ice world.” Roughly the size of Neptune, Gliese 436b is located much closer to its star (a red dwarf) at just 2.5 million miles. In comparison, Mercury is 29 million miles away from our Sun.

Gliese 436b is covered in hot, but solid, water, which occurs because the water is under such extremely high pressure. Under extremely high pressure, water turns into other solid states, and on this planet the exotic ice is being heated to several hundred degrees.

Recently, it was reported in Nature that Gliese 436b’s atmosphere is evaporating. Researchers had observed a large cloud of hydrogen gas emitting from the red dwarf, which was burning off the planet’s upper atmosphere. While the process doesn’t threaten the planet, it may help to explain the disappearance of atmospheres of terrestrial planets. The same thing could happen to Earth’s atmosphere, but at the end of the planet’s life when the Sun swells up to become a red giant.

The Darkest Planet

Astronomers discovered a planet blacker than coal in our own galaxy. The Jupiter-sized gas giant, named TrES-2b, is heated to 1,800 degrees Fahrenheit and reflects almost no light.

“TrES-2b is considerably less reflective than black acrylic paint, so it’s truly an alien world,” astronomer David Kipping of the Harvard-Smithsonian Center for Astrophysics lead author on the paper reporting the research, said in a statement at the time.

They are unsure what makes the planet so dark, but it isn’t actually pitch black. In fact, study co-author David Spiegel of Princeton University said that the hot planet emits a faint red glow. The planet, which orbits just 3 million miles away form its star, reflects less than 1% of the sunlight falling on it.

 

Planet Uranus

Located at least 1.6 billion miles away from Earth, Uranus is not usually visible with the naked eye and was the first planet discovered through the use of a telescope. Due to the planet’s axial tilt, it can seem as if the planet is rolling on its side during its 84 (Earth) year journey around the Sun. As a result of this tilt, the poles receive more sunlight than the equatorial regions.

Voyager 2, which is the only spacecraft to flow past Uranus, returned the first close-up images of the planet, its moons, and its rings in 1986. Uranus has 2 sets of rings that were probably formed when the planet’s moons were broken up in some impact.

The 27 moons of Uranus are not named after Greek mythology, rather they are named after characters from the works of William Shakespeare and Alexander Pope with the 5 main satellites being Miranda (from Shakespeare’s The Tempest), Ariel (named for both The Tempest and Pope’s The Rape of the Lock), Umbriel (from The Rape of the Lock), Titania, and Oberon (named for the fairy queen and king from Shakespeare’s A Midsummer’s Night Dream). All of these moons are known to be frozen with dark surfaces.

Uranus is one of the big gas giants, but is referred to as an “ice giant.” While its upper layer is hydrogen mixed with helium, like Saturn and Jupiter, the atmosphere contains more ices, such as water, ammonia, and methane, and the interior is mainly composed of rock and ice.

Although it is not the farthest planet from the Sun, Uranus actually has the coldest atmosphere in the Solar System with a minimum atmospheric temperature of -371 degrees Fahrenheit.

While there isn’t much of interest occurring on the planet’s surface, 2014 was a year of extreme storm activity on Uranus, according to researchers. They reported that all storms were in the northern hemisphere and one storm was incredibly bright, reflecting 30% as much light as the rest of the planet.

Since 2007, when the Sun shined directly on Uranus’ equator and lit up both poles, the planet has become more active, although scientists are unsure why there was a peak in activity in August 2014.

Uranus is has a mass of 86,810,300,000,000,000 billion kg, which is 14.5 times larger than that of Earth. Discovered in 1781, it is 19.22 AU and has 27 moons orbiting around it. Its temperature is around -190 °C.

Planet Venus

Named for the Roman goddess of love and beauty, the planet Venus has been known since prehistoric times because the planet is one of the brightest objects in the sky. (Only the Sun and the Moon are brighter.)

Although Venus is often called Earth’s sister planet, the two are radically different in very important ways. Despite being close to Earth in size and density, Venus is probably the least hospitable of our solar system’s planets.

The atmosphere is composed mostly of carbon and the several layers of clouds obscuring the planet’s surface are composed of sulphuric acid. Although the winds at the planet’s surface are estimated to be just a few miles per hour, the top layer of clouds are propelled by hurricane-force winds that travel roughly 224 miles per hour.

These clouds are so thick that they make the surface temperature run as hot as 870 degrees Fahrenheit, or hot enough to melt lead. There are more than 1,000 volcanoes or volcanic centers larger than 20 kilometers have been found on the planet’s surface.

Although Venus is nearly twice the distance from the Sun as Mercury, Venus’ surface is hotter. Like Mercury however, Venus has no moons.

Venus take 243 Earth days to rotate once on its axis, but the planet’s orbit around the Sun only takes 225 days, which means a day on Venus lasts longer than a year. Interestingly, the planet also rotates counter-clockwise, which may be because of a collision with an asteroid or other object.

The first spacecraft to visit Venus was Mariner 2 in 1962 and has been visited more than 20 times. Until scientists were able to observe and measure the planet’s temperatures in the 1960s, it was thought that Venus was a tropical paradise.

The Venus Express was launched by the European Space Agency in 2005 and spent 8 years in orbit around the planet. This past summer the spacecraft dipped into Venus’ upper atmosphere; however, the Venus Express is nearing the end of its life as it runs out of fuel. As it falls toward its death, expected to take place December 2014, it will continue to collect and return data on the planet.

Our Solar System’s Missing Planet: The Super-Earth

Exoplanet Comparisons
Not found in our galaxy is an Exoplanet – Larger than Earth. Smaller than Neptune

In other solar systems, the presence of super-Earths, planets that typically have a mass higher than Earth’s, but below Uranus, which is 15 Earth masses. Planets above 10 Earth masses are usually termed mega-Earths. Some of which are even in habitable zones, have been discovered. So far, we have found thousands, although only a few are actually close enough and orbiting bright enough stars for astronomers to study, currently.

In fact, research suggests that while smaller planets are more common than the big ones, these super-Earths  are actually the most common type of planet in the Universe.

And yet, there is no example of a super-Earth in our own Solar System.

“We are left with this situation where super-Earths appear to be the most common kind of exoplanet in the galaxy, but we don’t know what they’re made of,” Heather Knutson, assistant professor in the Division of Geological and Planetary Sciences at the California Institute of Technology, said in 2014.

The first super-Earths were discovered in 1992 with 2 outer planets that had masses approximately 4 times Earth. However, the first super-Earth discovered around a dwarf star occurred in 2005. In 2007, researchers discovered 2 super-Earths orbiting Gliese 581, both of which were on the edge of the habitable zone where liquid water may be possible on the surface.

As of December 2011, the Kepler Space Observatory Mission team had found 2,326 planetary candidates, 207 of which are of similar size to Earth, and 48 of which are in habitable zones of surveyed stars.

“Super-Earths are at the edge of what we can study right now,” Knutson said. “But super-Earths are a good consolation prize—they’re interesting in their own right, and they give us a chance to explore new kinds of worlds with no analog in our own solar system.”

So with astronomers finding Earth-like planets left and right in other solar systems, why doesn’t our Solar System have one?

There is a scenario, called the Nice model, that theorizes that Jupiter, Saturn, Uranus, and Neptune were originally found much more closely spaced and more compact than they currently are. However, their orbits moved outwards, and in doing so they continued to migrate the orbits of small, rock and ice planetesimals further outward. In fact, interaction with Jupiter’s immense gravity may have ejected some planetesimals right out of the Solar System.

Essentially, the thought is that we did once have super-Earths, but as our larger planets migrated out, they pushed those worlds out or may have even merged them. After moving out, the inner Solar System was left empty, and the worlds that grew inside it didn’t have the opportunity to grow larger than Earth and Venus.

It is theorized that had the movement of the gas giants not cleared out the outer Solar System and stunted the growth of the inner planets, there might be a super-Earth nearby and ripe for exploration.

Although the Nice model is not universally favored among planetary scientists, it is widely accepted as the current most realistic model of our Solar System’s early evolution.

Planet Mercury

Planet MecuryMercury, named after the Roman deity of finance and commerce, it is the closest and smallest planet to the sun. Being the closest to the sun, the star’s gravitational force is the strongest compared to the other plainest. So that Mercury does not fall into the sun, it orbit must rotate faster than the other planets; thus, Mercury speeds around the sun at a rate of 88 Earth days.

Mercury’s distance from the sun is .307 AU (average) and its surface temperature can range from 800 °F during the day to −280 °F at night. It rotates three times for every two revolutions around the sun. Mercury has no atmosphere and has no moons.

The planet has a great degree of craters that somewhat replicate the moon’s craters and this information helps scientists determine that this humanly inhabitable planet has been in this state for billions of years.

Any advanced creature that would live on Mercury would most likely have extremely large lungs to compensate for the atmosphere or to an opposite extent, have lungs that equate to fish. The creature would probably have a sort of skin that can accommodate very hot weather and very cold weather in one Mercurian day. Their eyes would be extremely small, since being so close to the sun would cast an immense brightness, similar to being on the beach or on white snow on a bright sunny day, but much more intense and their adaptable skin would most likely contain some type of protective coating to avoid sun burn.

It is difficult to see Mercury from Earth, due to its closeness to the sun. Humans have attempted to visit Mercury and two successful orbits were made by Mariner 10 and the MESSENGER spacecraft. Unfortunately, there were no signs of large lung creatures roaming about.