4 Planets in Our Solar System You've Probably Never Heard Of

An artist’s concept of Makemake. The dwarf planet is 870 miles across and was discovered in 2005. Image credit: NASA

On Monday, June 11, astronomers announced the discovery of a new dwarf planet beyond the orbit of Neptune. Temporarily named 2015 RR245 (scientists will eventually think of something snappier), not much is known about the trans-Neptunian object. "It's either small and shiny, or large and dull," said Michele Bannister of the University of Victoria, who is part of the discovery team.

Until humans build more powerful telescopes, this might be the last dwarf planet in our solar system to be observed for quite some time. But that's OK. There are four other already discovered planets orbiting our Sun that you might not know about (and several others that might one day be classified as such—especially 2007 OR10). Here they are.  


Artist's concept of Eris. Image credit: NASA/JPL-Caltech

When Mike Brown and his team at Palomar Observatory in San Diego discovered Eris in 2005, Pluto's categorization as a planet proper was suddenly brought up for debate. Eris was believed to be larger than Pluto (it's not, as New Horizons later revealed) and is certainly more massive, and astronomers were unhappy with the idea of dozens of planets orbiting our Sun when they could just redefine "planet," drop Pluto, and keep things much simpler. The New Horizons data has only intensified the debate. Pluto has clouds! Anyway, it's not like Pluto blew up Alderaan-style when it was re-categorized. It's still there, and on a long enough timeline, its scientific classification will be refined and improved. Not even Earth's status as a planet may be all that safe.

Eris is located in the Scattered Disc, a region of the solar system beyond the Kuiper Belt, which is itself a region of space beyond Neptune. Eris has one known moon, called Dysnomia (who is in Greek mythology the daughter of Eris). If you were to stand on Eris, you would almost certainly die, though before freezing to death you would have a hard time identifying the Sun. From that distance, the Sun appears only as a really bright star.


An artist's concept of Haumea and its moons, Hi'iaka and Namaka. Image credit: NASA

Located in the Kuiper Belt, Haumea is another Mike Brown discovery. It was observed in 2003 and announced in 2005. Haumea is one of the fastest-spinning objects in the solar system, and as a result, it has a distinct oblong shape (NASA describes it as being shaped like a "plump cigar"). The dwarf planet is named for a Hawaiian goddess, and its moons, Hiʻiaka and Namaka, are named for her daughters. Hiʻiaka is the patron goddess of the island of Hawaii (and of hula dancers), while Namaka is a water spirit. (Haumea's early, unofficial name among its discoverers was Santa, and its moons were Rudolph and Blitzen.) A single Haumean orbit takes 285 Earth years. Its surface albedo (or reflectivity) is suggestive of crystalline water ice—and a lot of it. The dwarf planet is as bright as snow, and as much as 80 percent of its surface might be covered in ice.


You've probably already guessed who discovered Makemake (seen at top in an artist's rendition), which is located in the Kuiper Belt and classified as a dwarf planet. Pronounced "mockey-mockey," the world has a 22.5-hour day similar to Earth's, but its year is 310 of ours. It also no atmosphere to speak of. This lack of an atmosphere was determined when Makemake crossed in front of a star, and surprised scientists, who expected it to be more Pluto-like given its midway proximity between Pluto (which has an atmosphere) and Eris (which does not).

Earlier this year, scientists using the Hubble Space Telescope discovered a dark moon in orbit around Makemake. They're calling the moon S/2015 (136472) 1. (It was observed by the telescope in April 2015.) For its part, Makemake is named for a god in Easter Island's Rapa Mui mythology. (The Kuiper Belt object's nickname among its discovery team was Easter Bunny.)


NASA/JPL-Caltech/UCLA/MPS/DLR/IDA, converted from Nature Publishing Group press’s YouTube channel

OK, you might have heard of Ceres; we wrote about it being fully mapped just a few months ago. Despite this mapping, many puzzles remain. Ceres is a dwarf planet in the Asteroid Belt whose vexing white spots have enthralled scientists and the public alike since 2015. (In the end, those spots turned out not to be extraterrestrial homing beacons but salts, possibly caused by water beneath the planet's surface.)

Ceres is the largest object in the Asteroid Belt and has been well explored by the Dawn spacecraft. Last week, NASA decided to extend Dawn's mission and see what happens as the ever-mysterious Ceres reaches perihelion—that is, the closest point in its elliptical orbit that it comes to the Sun. The Dawn team had hoped to leave Ceres's orbit and send the spacecraft to Adeona, another object in the Asteroid Belt. Dawn is already the first spacecraft to orbit two separate celestial bodies (Vesta and Ceres), and Adeona would have set the bar even higher for some future upstart orbit-happy spacecraft. For what it's worth, Mike Brown didn't discover Ceres, but that's likely only because Guisseppe Piazzi, who spotted it first, was born two centuries earlier. 

science fiction
Why So Many Aliens in Pop Culture Look Familiar

Aliens have been depicted countless times in cinema, from Georges Méliès's A Trip to the Moon (1902) to James Cameron's Avatar (2009). But despite the advancements in special-effects technology over the past century, most aliens we see on screen still share a lot of similarities—mainly, they look, move, and interact with the world like humans do. Vox explains how the classic alien look came to be in their new video below.

When you picture an alien, you may imagine a being with reptilian skin or big, black eyes, but the basic components of a human body—two arms, two legs, and a head with a face—are likely all there. In reality, finding an intelligent creature that evolved all those same features on a planet millions of light-years away would be an extraordinary coincidence. If alien life does exist, it may not look like anything we've ever seen on Earth.

But when it comes to science fiction, accuracy isn't always the goal. Creating an alien character humans can relate to may take priority. Or, the alien's design may need to work as a suit that can be worn by human performers. The result is a version of extraterrestrial life that looks alien— but not too alien—to movie audiences.

So if aliens probably won't have four limbs, two eyes, and a mouth, what would they look like if we ever met them person? These experts have some theories.

[h/t Vox]

A Year in Space Changed How Astronaut Scott Kelly's Genes Behaved

After spending 342 consecutive days onboard the International Space Station from 2015 to 2016, astronaut Scott Kelly now holds the record for longest single space mission by an American. But his "One-Year" study with NASA was about more than breaking records: Its purpose was to show how prolonged time in orbit would effect Kelly's genetic makeup compared to that of his identical twin brother on Earth. Now, following recent evaluations of the two men, it appears that Scott Kelly's gene expression was significantly altered by his time in space, reports.

NASA announced the most recent findings from its Twins Study ahead of a more comprehensive paper combining the work of multiple teams of researchers that is slated for later in 2018. Like his brother Scott, Mark is also an astronaut, making the pair the only twin astronauts in history. So when NASA was looking for a way to study the long-term effects of space life, the siblings were a perfect fit.

As Scott was sending tweets and blowing bubbles on the ISS, Mark stayed on Earth to serve as the control. Biological samples taken from both subjects before, during, and after the space flight showed some dramatic differences. According to an investigation conducted by Susan Bailey of Colorado State University, Scott's telomeres, the protective "cap" at the ends of chromosomes that shorten as we age, got longer in space. The telomeres began shrinking back to preflight levels, however, a few days after Scott's return to Earth. Scott was subjected to regular exercise and a restricted diet aboard the ISS, so the new lifestyle may explain the sudden telomere boost.

Other genetic differences stuck around even months after landing. "Although 93 percent of genes' expression returned to normal post-flight, a subset of several hundred 'space genes' were still disrupted after return to Earth," acccording to a NASA press release. About 7 percent of Scott's genes may show longer-term changes, included the genes associated with DNA repair, immune health, bone formation, hypoxia (an oxygen deficiency in the tissues) and hypercapnia (excessive carbon dioxide in the bloodstream).

A long list of factors, like radiation, caloric restriction, and zero gravity, may have contributed to the results. NASA plans to use these findings to develop countermeasures against these effects, which will be essential if the agency plans to send humans to Mars, a journey that could take three times as long as Scott Kelly's ISS mission.


Editor's note: We updated the headline and one line of this story to more accurately reflect the research findings. We apologize for the error. 


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