Solar System Archives

June 23, 2020June 23, 2020 by Evan Gough

Pluto and Other Kuiper Belt Objects Started Out With Water Oceans, and Have Been Slowly Freezing Solid for Billions of Years

Far left: Pluto and it's heart-shaped feature called “Tombaugh Regio” in honor of astronomer Clyde Tombaugh, who discovered the dwarf planet. The bright expanse of the western lobe of Pluto’s “heart” is informally called Sputnik Planum. Above left: Pluto’s surface sports a remarkable range of landforms that have their own distinct colors, telling a complex geological and climatological story. Credit: Courtesy NASA / JHUAPL / SwRI Table of Contents page 2015 Annual Report Division: (15)

It seems unlikely that an ocean could persist on a world that never gets closer than 30 astronomical units from the Sun. But that’s the case with Pluto. Evidence shows that it has a sub-surface ocean between 100 to 180 km thick, at the boundary between the core and the mantle. Other Kuiper Belt Objects may be similar.

But time might be running out for these buried oceans, which will one day turn to ice.

June 19, 2020June 19, 2020 by Evan Gough

NASA Thinks it’s Time to Return to Neptune With its Trident Mission

Artist's impression of what the surface of Triton may look like. Credit: ESO

Is it time to head back to Neptune and its moon Triton? It might be. After all, we have some unfinished business there.

It’s been 30 years since NASA’s Voyager 2 spacecraft flew past the gas giant and its largest moon, and that flyby posed more questions than it answered. Maybe we’ll get some answers in 2038, when the positions of Jupiter, Neptune, and Triton will be just right for a mission.

June 16, 2020June 16, 2020 by Evan Gough

New Pictures of Phobos, Seen in the Infrared

Six views of the Martian moon Phobos captured by NASA's Odyssey orbiter as of March 2020. The orbiter's THEMIS camera is used to measure temperature variations that suggest what kind of material the moon is made of. Credit: NASA/JPL-Caltech/ASU/NAU

NASA’s Mars Odyssey Orbiter doesn’t get a lot of headlines lately. It was sent to Mars in 2001, to detect the presence of water and ice on Mars, or the past presence of it. It also looked at Mars’ geology and radiation. It’s been doing its job without a lot of fanfare.

Now Odyssey’s infrared camera has given us three new images of Mars’ moon Phobos.

June 11, 2020June 11, 2020 by Evan Gough

Titan is Drifting Away from Saturn Surprisingly Quickly

Titan in front of Saturn. Image Credit: NASA/JPL-Caltech/Space Science Institute

Where did Saturn’s bizarro-moon Titan form? Did it form where it is now, or has it migrated? We have decades of data to look back on, so scientists should have some idea.

A new study based on all that data says that Titan is drifting away from Saturn more quickly than thought, and that has implications for where the moon initially formed.

May 29, 2020May 29, 2020 by Evan Gough

Maybe the Elusive Planet 9 Doesn’t Exist After All

The imagined view from Planet Nine looking back toward the sun. Astronomers think the huge, distant planet is gaseous, similar to the other giant planets in our solar system.

Oh Planet Nine, when will you stop toying with us?

Whether you call it Planet Nine, Planet X, the Perturber, Jehoshaphat, “Phattie,” or any of the other proposed names—either serious or flippant—this scientific back and forth over its existence is getting exhausting.

Is this what it was like when they were arguing whether Earth is flat or round?

May 27, 2020May 27, 2020 by Evan Gough

The Solar System Might Not Exist if There Wasn’t a Huge Galactic Collision with the Milky Way Billions of Years Ago

Artist's conception of a solar system in formation. It's likely that exoplanet formation around other stars proceeded similarly. Credit: NASA/FUSE/Lynette Cook

The Milky Way has a number of satellite galaxies; nearly 60 of them, depedending on how we define them. One of them, called the Sagittarius Dwarf Spheroidal Galaxy (Sgr d Sph), may have played a huge role when it comes to humans, our world and our little civilization. A collision between the Milky Way and the Sgr d Sph may have created the Solar System itself.

May 21, 2020May 22, 2020 by Paul M. Sutter

Jupiter is so Big that our Solar System almost had two Suns

Europa and Io move across the face of Jupiter, with the Great Red Spot behind them. Image: NASA/JPL/Cassini, Kevin M. Gill

About half of all the star systems in the galaxy are made of pairs or triplets of stars. Our solar system features just one star, the Sun, and a host of (relatively) small planets. But it was almost not the case, and Jupiter got right on the edge of becoming the Sun’s smaller sibling.

Jupiter, the biggest planet in the solar system, is by far the largest. If you added up the masses of all the other planets, it wouldn’t even come to half of the mass of Jupiter. You could eliminate every single planet in the solar system except Jupiter, and you would basically still have…the solar system.

February 21, 2020February 21, 2020 by Evan Gough

Nutrient-Poor and Energy-Starved. How Life Might Survive at the Extremes in the Solar System

Artist impression of a sunset over KELT-9b, where the planet’s atmosphere is hot enough to vaporize heavy metals such as iron and titanium. Credit and ©: Denis Bajram

Our growing understanding of extremophiles here on Earth has opened up new possibilities in astrobiology. Scientists are taking another look at resource-poor worlds that appeared like they could never support life. One team of researchers is studying a nutrient-poor region of Mexico to try to understand how organisms thrive in challenging environments.

January 24, 2020January 24, 2020 by Evan Gough

OSIRIS-REx Flew 620 Meters Above its Landing Site. Confirms that it’s a Boulder-Strewn Nightmare, Just Like the Rest of Bennu

Image obtained on Mar. 7th by the PolyCam camera on NASA’s OSIRIS-REx spacecraft from a distance of about 5 km (3 mi) Credit: NASA/Goddard/University of Arizona

NASA’s OSIRIS-REx spacecraft reached its target, asteroid Bennu (101955 Bennu), on December 3rd, 2018. Since then, the spacecraft has been examining the asteroid’s surface, looking for a suitable landing spot to collect a sample. The problem is, Bennu has a much rockier and challenging surface than initially thought.

December 11, 2019December 11, 2019 by Evan Gough

We Know We’re Made of Stardust. But Did it Come From Red Giants?

Artist's impression of a red giant star. If the star is in a binary pair, what happens to its sibling? Credit:NASA/ Walt Feimer

We’ve all heard this one: when you drink a glass of water, that water has already been through a bunch of other people’s digestive tracts. Maybe Attila the Hun’s or Vlad the Impaler’s; maybe even a Tyrannosaurus Rex’s.

Well, the same thing is true of stars and matter. All the matter we see around us here on Earth, even our own bodies, has gone through at least one cycle of stellar birth and death, maybe more. But which type of star?

That’s what a team of researchers at ETH Zurich (Ecole polytechnique federale de Zurich) wanted to know.