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CNN — The Curiosity rover is moving on, the Hubble Space Telescope made an accidental discovery, and a mysterious object was found on the edge of the solar system — and that's just some of what happened in space this week.
And then there's the cave that's helping to rewrite human history and a dinosaur fossil found in Antarctica.
Let's take a peek at some of the amazing discoveries made on good ol' Earth and beyond over the past few days.
Rover's going to keep on rovin'
NASA's Curiosity rover took its final selfie on Vera Rubin Ridge, its home on Mars since September 2017. The drill samples and photos from this location have given scientists a lot to study about Mars and the twisted ridge between Gale Crater and Mount Sharp.
But fear not; the selfies will continue. Now, the rover is heading to a trough south of the ridge that's full of clay minerals. Those are probably leftovers from ancient lakes on Mars that could have helped form the lower levels of Mount Sharp.
This week, it was also revealed that scientists repurposed an instrument on Curiosity to learn more about how Gale Crater and Mount Sharp formed.
In sadder news, the dedicated project team for the Opportunity rover on Mars is sending new commands in hopes of waking it up. Opportunity, or Oppy as she's known, has been unresponsive since a planet-encircling dust storm took over Mars in June. The good news: Oppy's team isn't giving up the fight just yet. Come through, Oppy!
Loneliest 'living fossil' galaxy
A sure sign that the Hubble Space Telescope is up and running at full steam again is a pretty picture — and a discovery, of course. The venerable telescope has been looking around the universe and revealing discoveries since 1990.
But the universe isn't as sparse as you might think. When Hubble peeks around, it's more like looking through a crowded neighborhood where some objects block others from view.
Hubble was taking snapshots of a globular star cluster NGC 6752, which is 13,000 light-years away in the Milky Way's halo, when it spotted a dwarf galaxy behind the crowded cluster. All by itself, this never-before-seen galaxy is just hanging out in our backyard, about 30 million light years away.
It may be the most isolated dwarf galaxy ever found. Lonely isn't a bad thing in the universe; that means it hasn't been smashed up or eaten by other, bigger galaxies.
For now, astronomers are calling it Bedin 1. The small galaxy is only a fraction of the size of our own. It's nearly as old as the universe, at about 13 billion years, and due to its isolation, astronomers look at it like a "living fossil" from the beginning of the universe.
Meet the 'Antarctic king'
You probably didn't expect dinosaurs to live in Antarctica. It's not exactly a friendly climate for reptiles. But it wasn't always so frosty and inhospitable. About 250 million years ago, it was downright cozy and covered with forests and rivers.
A new fossil found in Antarctica, given a name that translates to "Antarctic king," was an iguana-sized dinosaur relative called an archosaur that munched on amphibians and bugs. This was a diverse time for life, about 2 million years after the largest known mass extinction on Earth. After that, evolution sped up, and all kinds of species appeared.
"Antarctica had a combination of these brand-new animals and stragglers of animals that were already extinct in most places — what paleontologists call 'dead clades walking.' You've got tomorrow's animals and yesterday's animals, cohabiting in a cool place," said Brandon Peecook, lead study author and Field Museum researcher.
To the sun and beyond
That's right, it's our good friend Ultima Thule! Long time, no see. But if you don't remember, it's the distant Kuiper Belt Object about a billion miles past Pluto that NASA's New Horizons mission flew past on New Year's Day.
And this is the sharpest we've seen it. Expect more cool images and new information about it soon.
And speaking of awesome missions, the Parker Solar Probe recently completed its first orbit of the sun. The second orbit will begin in April.
"We've always said that we don't know what to expect until we look at the data," Project Scientist Nour Raouafi said. "The data we have received hints at many new things that we've not seen before and at potential new discoveries. Parker Solar Probe is delivering on the mission's promise of revealing the mysteries of our Sun."
A cave of mysteries
It's the only place in the entire world where the remains of some of the first humans, called Denisovans, have been found. And now we're learning more about the history this cave truly contains.
A timeline has now been established for Denisova Cave, in the foothills of Siberia's Altai Mountains, and it's believed to have sheltered Neanderthals and Denisovans at different times from about 300,000 to 50,000 years ago. The researchers believe the Neanderthals and Denisovans met and interbred 100,000 years ago, producing at least one child that they know of.
New dating techniques, as well new fossils, helped make this timeline possible. But with new insight comes new questions, and the researchers will continue looking for more evidence. Until then, we know the Denisovans by only a handful of fragmented fossils.
What's that at the edge of the solar system?
It's not an alien, but it's weird. And scientists are pretty excited to know something that was predicted to exist for more than 70 years is real.
For the first time, a body has been found on the edge of the solar system that helps fill the gap in planet formation. The size is key; its radius is 1.3 kilometers (0.8 miles). That makes it a stepping stone between bundles of dust and ice and fully formed planets.
Beyond Neptune's orbit are the Kuiper Belt Objects, one of which is Pluto. These objects live in a cold, dark place, untouched by anything else, and act like records from the early solar system. But they're small, distant and faint, which makes them hard to spot with telescopes. A new method called occultation takes a large number of stars and looks for shadows of objects to pass by, which made this discovery possible.
And now, researchers think that this building block they found could be just one of many.
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