Asteroids come in all shapes and sizes; some are big enough to earn the title of dwarf planet while others are about the size of an ostrich† These wandering rocks are incredibly important objects for scientists seeking information about the formation of the solar system and even life on Earth. Some meteorites (the space rocks that fall to Earth) contain amino acids, and many asteroids contain evidence that they ever carried water† The history of life on Earth could theoretically be attributed to a few luckily fallen rocks.
We’ve only visited a few asteroids so far, but NASA is working to change that. It launched the Lucy spacecraft last year, exploring Jupiter’s Trojan asteroids, a mission that will give us a whole new understanding of these strange objects. Lucy has already returned some epic postcards (click through to this article to see them) and Lucy is expected to reach the Trojan asteroids in 2027.
2027 is still a ways away, but Lucy will send us some goodies along the way. Until then, we’ll have to deal with the space rocks we’ve already seen up close.
Ceres is huge as far as asteroids go, making up 25% of the asteroid belt between Mars and Jupiter on its own. In fact, Ceres is now classified as a dwarf planet and was visited by the Dawn spacecraft in 2015. That trip gave researchers fantastic images of the spherical object, one that still has water — making it a particularly intriguing candidate for life.
The 2014 Apollonian asteroid JO25 is an oddly shaped space rock that orbits approximately every 4.5 hours. It was observed up close by the since-destroyed Arecibo Observatory in April 2017, when the object was just over a million miles from Earth, the will be closest for four centuries. The observations offer a unique perspective on what life is like for a space rock: These objects appear stately in still images, but in fact they hurtle through space at breakneck speeds, spinning all the time.
If you look too fast, you could confuse Vesta with the moon. The second largest object in the asteroid belt after Ceres, Vesta, was also visited by Dawn† It is unique from other asteroids in that it has its own crust, mantle and core, which scientists say is because the asteroid is so old.
Eros was the first asteroid discovered near Earth, accidentally appearing on a photographic plate in 1898. It was also the first asteroid to be imaged by a spacecraft in orbit, after being photographed by the NEAR spacecraft for a century in 1998. after its discovery. And to make it a trifecta of firsts, the spacecraft also landed on Eros in 2001 — the first spacecraft landing on an asteroid — allowing astronomers to use Eros to calculate the astronomical unit, a commonly used measure of the solar system.
Bennu has dominated heads in recent years thanks to the ongoing mission of OSIRIS-REx. That ongoing seven-year mission has seen a spacecraft orbiting Bennu, sampling it, and… begin his journey back to earth† If successfully completed, the mission will be the largest amount of extraterrestrial material brought to Earth since the Apollo missions, and the samples are for sure to reveal new clues to the history of the solar system, if not the origin of life.
Ida is the first asteroid known to have its own moon, a small piece of rock called Dactyl. It is thought to be a piece of debris from an ancient collision between two larger objects. Ida (and Dactyl, whose discovery was) somewhat coincidental) are part of the Koronis family of asteroids in the main belt between Mars and Jupiter.
In 2019, the Hubble Space Telescope captured something astonishing: the destruction of a 5 km wide asteroid called Gault, which spewed huge streams of dust in its wake. Although this drama could have started long ago – on the order of a a hundred million years – these events can gradually pick up steam. Gault isn’t gone yet, but we’re lucky we got a look at it via Hubble as it completes its final dance.
OK, so this last slide isn’t really an asteroid. But it’s so cool that we’re making an exception. Comet 67P/Churyumov-Gerasimenko actually landed in 2014 by the ESA Philae spacecraft, part of the Rosetta probe, and the images are incredible. Dust and debris filter around the comet, making it resemble a snowy mountain peak.
Amazing time lapse of footage from the #Rosetta probe flies 13 km above comet 67P. A mix of stars, dust and ice particles, space debris. Stitched together/Credit: Jacint Roger Perez pic.twitter.com/z1GDICfoNN
— Project adrift (@ProjectAdrift) April 28, 2018
This article has been updated since it was first published.
#closer #epic #photos #asteroids