Asteroids come in all shapes and sizes; some are large enough to merit the title of dwarf planet, while others are about the size of an ostrich. These wandering rocks are incredibly important objects for scientists looking for information about the formation of the solar system and even life on Earth. Some meteorites (space rocks that fall to Earth) contain amino acids, and many asteroids contain evidence that they when transported from the water. The history of life on Earth could be traced to a few lucky rockfalls, in theory.
We’ve only visited a few asteroids so far, but NASA is working to change that. This launched the Lucy spacecraft last year, which is exploring Jupiter’s Trojan asteroids, a mission that will bring us a whole new understanding of these strange objects. Lucy has already rendered epic postcards (click on this article to see them) and Lucy is expected to reach the Trojan asteroids in 2027.
2027 is a bit far, but Lucy will send us more gifts along the way. Until then, we will have to take care of the space rocks that we have already seen up close.
Ceres
Ceres is gargantuan when it comes to asteroids, alone accounting for 25% of the asteroid belt between Mars and Jupiter. In fact, Ceres is now classified as a dwarf planet and was visited by the Dawn spacecraft in 2015. This trip gave researchers fantastic images of the spherical object, one that still has water — making him a particularly intriguing candidate for life.
OJ25 2014
Apollonian asteroid 2014 JO25 is an oddly shaped space rock that rotates approximately every 4.5 hours. It was closely observed in April 2017 by the Arecibo observatory, since destroyed, when the object was just over a million kilometers from Earth, the the closer it will be for four centuries. The observations offer a unique perspective on what life is like for a space rock: Seemingly sculptural in still images, these objects are actually hurtling through space at breakneck speeds, spinning all the time.
Vesta
If you look too fast, you might mistake Vesta for 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 believe is due to the asteroid being so old.
Eros
Eros was the first near-Earth asteroid to be discovered, accidentally appearing on a photographic plate in 1898. It was also the first asteroid to be photographed by an orbiting spacecraft, having been the subject of a photo op by the NEAR spacecraft in 1998, a century after its discovery. And to make it a trio 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 well-used criterion for the solar system.
Bennu
Bennu has dominated headlines for two years thanks to the ongoing OSIRIS-REx mission. This ongoing seven-year mission has seen a spacecraft orbit Bennu, extract samples and begin its journey back to Earth. If the mission is successful, it will be the largest amount of extraterrestrial material brought to Earth since the Apollo missions, and the samples are safe reveal new clues to the history of the solar system, if not the origin of life.
Ida
Ida is the first known asteroid to have its own moon, a small piece of rock named Dactyl. It is believed to be a piece of debris from an ancient collision between two larger objects. Ida (and Dactyl, whose discovery was a bit fortuitous) are part of the Koronis family of asteroids in the main belt between Mars and Jupiter.
Gault
In 2019, the Hubble Space Telescope captured something amazing: the destruction of a 5 km wide asteroid named Gault, which was ejecting huge billows of dust in its wake. If this drama could have started a long time ago – on the order of a hundred million years – these events can become more serious over time. Gault hasn’t left yet, but we’re lucky to have caught a glimpse of him via Hubble as he completes his last dance.
Comet 67P/Churyumov–Gerasimenko
OK, so that last slide isn’t really an asteroid. But it’s so cool that we make an exception. Comet 67P/Churyumov-Gerasimenko was actually landed in 2014 by ESA’s Philae spacecraft, part of the Rosetta probe, and the images are incredible. Dust and debris filter around the comet, making it look like a snow-capped peak.
Incredible time-lapse footage from the #Rosette probe flying 13km above comet 67P. A mixture of stars, dust and ice particles, space debris. Sewn 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.
#epic #photos #asteroids #close