Solar System Archives

September 17, 2020September 17, 2020 by Evan Gough

Check Out How Big the Planets and the Moon Will be in Our Sky Over the Next Two Years

This is a screenshot of a data visualization video. It shows the apparent sizes of Solar System objects from our Earthly vantage point. Image Credit: James O'Donoghue

Everything in space is moving. Galaxies collide and merge, massive clouds of gas migrate, and asteroids, comets, and rogue planets zip around and between it all. And in our own Solar System, the planets follow their ancient orbits.

Now a new data visualization shows us just how much our view from Earth changes in two years, as the orbits of the planets change the distance between us and our neighbours.

September 16, 2020September 16, 2020 by Nancy Atkinson

Sunrises Across the Solar System

Saturn’s upper atmosphere. Processed using calibrated narrow-angle near-infrared (CB3) and ultraviolet (UV3) and wide-angle red, green, and violet filtered images of Saturn taken by Cassini on November 17 2007. NASA/JPL-Caltech/SSI/CICLOPS/Kevin M. Gill.

Scientists have learned a lot about the atmospheres on various worlds in our Solar System simply from planetary sunrises or sunsets. Sunlight streaming through the haze of an atmosphere can be separated into its component colors to create spectra, just as prisms do with sunlight. From the spectra, astronomers can interpret the measurements of light to reveal the chemical makeup of an atmosphere.

September 10, 2020September 10, 2020 by Evan Gough

Jupiter Probably Has 600 Small, Irregular Moons

Europa, Callisto, and Io in front of Jupiter in January 2015. Image Credit: NASA/JPL

The better our technologies get, the better we get at finding objects in space. That’s certainly true of Jupiter and its moons. Prior to Galileo, nobody knew the other planets had moons. Then in 1609/10, as he made improvements to his telescope, he aimed it at the gas giant and eventually found four moons: Io, Europa, Ganymede, and Callisto. Now those four natural satellites also bear his name: the Galilean moons.

Over the centuries since then, and especially in our digital age, astronomical tools and methods kept improving. In particular, wide-field CCD (Charge Coupled Devices) have led to an explosion of astronomical discoveries. In recent years, the confirmed number of Jovian moons has risen to 79. Now, a new study says that there may be 600 small irregular moons orbiting Jupiter.

August 7, 2020August 7, 2020 by Evan Gough

This is What the Solar System Really Looks Like

An updated model suggests the shape of the Sun’s bubble of influence, the heliosphere (seen in yellow), may be a deflated croissant shape, rather than the long-tailed comet shape suggested by other research. Credits: Opher, et al

At first glance, it looks like something from an alien autopsy. A strange organ cut from a xenomorph’s thorax, under the flickering lights of an operating room in a top secret government facility, with venous tendrils dangling down to the floor, dripping viscous slime. (X-Com anyone?)

But no, it’s just our Solar System.

July 29, 2020July 29, 2020 by Evan Gough

A Group of Meteorites All Came From a Destroyed Planetesimal With a Magnetic Core

Samples from a rare meteorite family, including the one shown here, reveal that their parent planetesimal, formed in the earliest stages of the solar system, was a complex, layered object, with a molten core and solid crust similar to Earth. Photo credit: Carl Agee, Institute of Meteoritics, University of New Mexico. Background edited by MIT News.

Before our Solar System had planets, it had planetesimals. Scientists think that most of the meteorites that have struck Earth are fragments of these planetesimals. Scientists also think that these planetesimals either melted completely, very early in their history, or that they remained as little more than collections of rocks, or “rubble piles.”

But one family of meteorites, that have been found spread around the world, appear to come from a planetesimal that bucked that trend.

July 10, 2020July 10, 2020 by Evan Gough

If Planet 9 is a Primordial Black Hole, We Might Be Able to See Flares When it Consumes Comets

Artist's conception of accretion flares resulting from the encounter of an Oort-cloud comet and a hypothesized black hole in the outer solar system. Credit: M. Weiss

A comet-eating black hole the size of a planet? It’s possible. And if there’s one out there in the distant Solar System, a pair of researchers think they know how to find it.

If they do, we might finally put the Planet 9 issue to rest.

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.