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. 

NASA Has a Plan to Stop the Next Asteroid That Threatens Life on Earth

An asteroid colliding catastrophically with Earth within your lifetime is unlikely, but not out of the question. According to NASA, objects large enough to threaten civilization hit the planet once every few million years or so. Fortunately, NASA has a plan for dealing with the next big one when it does arrive, Forbes reports.

According to the National Near-Earth Object Preparedness Strategy and Action Plan [PDF] released by the White House on June 21, there are a few ways to handle an asteroid. The first is using a gravity tractor to pull it from its collision course. It may sound like something out of science fiction, but a gravity tractor would simply be a large spacecraft flying beside the asteroid and using its gravitational pull to nudge it one way or the other.

Another option would be to fly the spacecraft straight into the asteroid: The impact would hopefully be enough to alter the object's speed and trajectory. And if the asteroid is too massive to be stopped by a spacecraft, the final option is to go nuclear. A vehicle carrying a nuclear device would be launched at the space rock with the goal of either sending it in a different direction or breaking it up into smaller pieces.

Around 2021, NASA will test its plan to deflect an asteroid using a spacecraft, but even the most foolproof defense strategy will be worthless if we don’t see the asteroid coming. For that reason, the U.S. government will also be working on improving Near-Earth Object (NEO) detection, the technology NASA uses to track asteroids. About 1500 NEOs are already detected each year, and thankfully, most of them go completely unnoticed by the public.

[h/t Forbes]

Frederick M. Brown, Getty Images
Stephen Hawking’s Memorial Will Beam His Words Toward the Nearest Black Hole
Frederick M. Brown, Getty Images
Frederick M. Brown, Getty Images

An upcoming memorial for Stephen Hawking is going to be out of this world. The late physicist’s words, set to music, will be broadcast by satellite toward the nearest black hole during a June 15 service in the UK, the BBC reports.

During his lifetime, Hawking signed up to travel to space on Richard Branson’s Virgin Galactic spaceship, but he died before he ever got the chance. (He passed away in March.) Hawking’s daughter Lucy told the BBC that the memorial's musical tribute is a “beautiful and symbolic gesture that creates a link between our father's presence on this planet, his wish to go into space, and his explorations of the universe in his mind.” She described it as "a message of peace and hope, about unity and the need for us to live together in harmony on this planet."

Titled “The Stephen Hawking Tribute,” the music was written by Greek composer Vangelis, who created the scores for Blade Runner and Chariots of Fire. It will play while Hawking’s ashes are interred at Westminster Abbey, near where Isaac Newton and Charles Darwin are buried, according to Cambridge News. After the service, the piece will be beamed into space from the European Space Agency’s Cebreros Station in Spain. The target is a black hole called 1A 0620-00, “which lives in a binary system with a fairly ordinary orange dwarf star,” according to Lucy Hawking.

Hawking wasn't the first person to predict the existence of black holes (Albert Einstein's general theory of relativity accounted for them back in the early 1900s), but he spoke at length about them throughout his career and devised mathematical theorems that gave credence to their existence in the universe.

Actor Benedict Cumberbatch, a friend of the Hawking family who portrayed the late scientist in the BBC film Hawking, will speak at the service. In addition to Hawking's close friends and family, British astronaut Tim Peake and several local students with disabilities have also been invited to attend.

[h/t BBC]


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