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| SOL 1598 MR+ML (Seán Doran) |
Opportunity, Spirit, and Curiosity Rovers
NASA has three rovers active on Mars right now. The Opportunity Rover landed in 2004 and was only expected to operate for 90 days, but is still exploring and sending back pictures today, more than twelve years later. Its partner, Spirit, is also still running, but is stuck in sand and has been unable to move for over a decade. The Curiosity Rover landed in 2012 and is currently searching for organic material.
Two digital artists—Kevin Gill and Seán Doran—have been using data from these and other Mars missions to create beautiful images of what Mars’ terrain looks like from the air and from the ground. Gill’s Flickr gallery is here and Doran’s gallery is here.
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| Hexagonal clouds on Saturn's north pole (NASA) |
Cassini Spacecraft and Huygens Probe
NASA’s Cassini spacecraft was launched in 1997. It passed Venus and Jupiter before arriving at Saturn and inserting itself into orbit around the planet in 2004. So far it has discovered at least two new rings and two new moons, as well as odd solid bodies in the rings that may be more satellites. It has also taken innumerable pictures of Saturn’s strange storms and distinctive hexagonal north pole cloud patterns.
One of the first things Cassini did upon arrival at Saturn was to deploy a probe, Huygens, which landed on Saturn’s moon Titan; this was the most distant landing ever by an Earth spacecraft on another world. Huygens took pictures the entire time, and NASA put these pictures together into a video, which is great; you can even see the shadow of the probe’s parachute sailing by after it lands on the surface. Because we already knew that Titan had lakes of methane on its surface, Huygens was built to float, but it landed on dry land and survived to take pictures for 72 hours
While Huygens was landing on Titan, Cassini itself was investigating another moon, Enceladus. It saw icy jets and geysers ejecting particles at high speed, leading scientists to discover that not only does Enceladus have an atmosphere, but it also has a liquid ocean under its surface ice—an ocean that could, conceivably, be capable of supporting life.
Cassini will keep studying Saturn until later this year, at which point it will be directed to plunge into Saturn’s atmosphere and destroy itself.
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| Jupiter's south pole (NASA/ JPL-Caltech/SwRI/MSSS/John Landino) |
Juno Orbiter
NASA’s Juno orbiter arrived at Jupiter in 2016 and settled itself into a large, long orbit around the planet. It is a polar orbit, which means that instead of orbiting in parallel with all of the planets revolving around the sun, it is orbiting across the solar plane, at right angles to it.
This enables the spacecraft to spend as little time in Jupiter’s destructive radiation fields as long as possible. On each orbit, it takes about 2 hours for the craft to go from the north pole to the south pole, and it travels less than 3,000 miles above the planet's clouds. It will be making a total of 37 orbits over 20 months before it suffers irretrievable damage to its instruments from Jupiter's radiation. After its 37th orbit, Juno will perform a controlled deorbit and plunge into Jupiter's atmosphere, where it will disintegrate.
NASA created a good (if somewhat overdramatic) explanatory documentary on the Juno mission.
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| Where is OSIRIS-REx now? (NASA) |
OSIRIS-REx Sample Retrieval Mission, Dawn Mission, Hayabusa 2 Spacecraft
Perhaps the most stunning of the various asteroid projects going on right now is NASA’s OSIRIS-REx sample retrieval mission. OSIRIS-REx is currently en route to the Bennu Earth-Trojan asteroid and will arrive there in August 2018. It will retrieve samples from the asteroid and return them to Earth in 2023, becoming the first US spacecraft to return samples from an asteroid. As it travels, it has been sending back pictures of other planets and moons in our solar system, including some of Earth and our moon together which make me oddly sentimental.
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| Occator Crater on Ceres (NASA/ JPL-Caltech/UCLA/MPS/DLR/IDA) |
The Hayabusa 2 spacecraft, built by the Japanese space agency (JAXA), is currently en route to the Ryugu asteroid and should arrive in July 2018.
And, finally, NASA is gearing up to launch a mission called “Lucy” in 2021, which will explore other Earth-Trojan asteroids.
Note: The term "Trojan asteroid" used to only refer to asteroids orbiting the sun in step with Jupiter, but now refers to a stable asteroid orbiting the sun in step with any planet. Thus an “Earth-Trojan asteroid” is an asteroid that is locked in orbit with Earth.
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| Pluto's Wright Mons (NASA/JHUIAPL/SwRI) |
New Horizons Spacecraft
NASA’s New Horizons spacecraft sailed past Charon and Pluto in 2015, taking pictures the whole time. It is the first spacecraft to study Pluto up close, and will now be studying the rest of the Kuiper Belt. It is the fastest artificially-accelerated object ever, and will be the fifth probe to leave the solar system. NASA put together a video of what a virtual “landing” on Pluto would look like, based on pictures from New Horizons, here.
Favorite Ongoing Space Mission #6: Venus
Akatsuki Orbiter
JAXA’s Akatsuki orbiter is currently orbiting Venus. It arrived in 2010 and, after some hitches, was able to be inserted into Venusian orbit in 2015. It is currently engaged in a 2-year period of science operations which will end in 2018. This is Japan’s first successful mission to explore another planet, and we wait with baited breath to see what they find out.
