The First Close-Up Image of Pluto Is Here


Water ice mountains 11,000 feet tall. No impact craters. The provocative possibility that Pluto's surface is much, much younger than we thought—and that the planet is still geologically active. So too is Charon, one of its four moons.

These are just a few of the conclusions scientists on the New Horizons mission are drawing from the first closeup images of Pluto and two of its moons. After a journey of 9.5 years and 3 billion miles, yesterday NASA’s New Horizons spacecraft got within 7800 miles of the surface, the closest encounter with Pluto the human race has ever had. Its scientific payload went into high gear as the probe flew by at more than 30,000 miles an hour, taking in reams of data via seven high-tech instruments.   

The probe was out of contact with mission headquarters for 13 hours so it could focus on gathering rather than transmitting data. When it reestablished contact last night at 8:52:37 p.m. ET, there was jubilation at the Johns Hopkins University's Applied Physics Laboratory (APL), mission headquarters. All the systems reported back as normal. "We have a healthy spacecraft," said Alice Bowman, mission operations manager.

Now we're seeing the first images from that superfast data grab. The new black-and-white image of Pluto shows a mountain range made of water ice, with peaks jutting as high as the Rocky Mountains, the team says. Here's a close up:

"The most striking thing is that we haven't found a single impact crater, which means this is a very young surface—less than 100 million years old," project scientist John Spencer said in a NASA press briefing. Collisions and the resulting impact craters were common in the volatile early years of our solar system's formation.

"It's clear that Pluto has remarkably varied terrain, and that the different colorations and textures of the large surface features point to diverse geological processes—surprising, perhaps, in a planet with so little external energy coming from the sun," Gettysburg College astronomer and professor emeritus Lawrence Marschall, co-author of Pluto Confidential, tells mental_floss. "The strong tidal interaction of Charon and Pluto may be responsible for the geological diversity you see. The very high mountains are particularly impressive."

We also spoke to the man responsible for Pluto's demotion to a dwarf planet: Mike Brown, the CalTech planetary astronomer whose discovery in 2005 of the planet Eris led to Pluto's reclassification as a dwarf planet. Because Eris was thought to be bigger than Pluto, some floated the idea that Eris be considered the 10th planet in the solar system. Instead, Pluto was "demoted," angering schoolchildren everywhere. (Eris, too, is considered a dwarf planet.)  

Brown calls the ice mountains on Pluto "very strange," but he doubts they are as young as the New Horizons team thinks. "It seems to me that they could be old mountains poking through some young icy terrain," he says. "The footprint of the mountains is so small that you'd have a hard time finding a crater on one even if it were there."

Brown's Twitter handle may be @plutokiller, but he was struck by the image of Charon. Here it is:

"My first thought upon opening up the Charon image was: 'Where are all of the impact craters?'" says Brown. Like Pluto, Charon's surface seems to be relatively baby-faced among objects in the solar system. "Pretty cool: we've known for 15 years that there would be ancient ice floes on the surface, but I would have thought that they were ancient enough that they were still covered in craters. Seems like the ice floes were more recent."

We'll have more details about the discoveries coming soon from contributor David Brown, who spoke to scientists at the NASA press briefing. Stay tuned.

In the meantime, consider that New Horizons is already more than a million miles past Pluto. It now heads into the Kuiper Belt, a gigantic zone of icy bodies and mysterious small objects orbiting beyond Neptune, where it will explore the origins of the outer solar system and how planet-satellite systems evolve. Because it's so energy efficient, New Horizons could, in theory, send us data for the next 30 years.

Scott Butner, Flickr // CC BY-NC-ND 2.0
Look Up! The Lyrid Meteor Shower Arrives Saturday Night
Scott Butner, Flickr // CC BY-NC-ND 2.0
Scott Butner, Flickr // CC BY-NC-ND 2.0

There is a thin line between Saturday night and Sunday morning, but this weekend, look up and you might see several of them. Between 11:59 p.m. on April 21 and dawn on Sunday, April 22, the Lyrid meteor shower will peak over the Northern Hemisphere. Make some time for the celestial show and you'll see a shooting star streaking across the night sky every few minutes. Here is everything you need to know.


Every 415.5 years, the comet Thatcher circles the Sun in a highly eccentric orbit shaped almost like a cat's eye. At its farthest from the Sun, it's billions of miles from Pluto; at its nearest, it swings between the Earth and Mars. (The last time it was near the Earth was in 1861, and it won't be that close again until 2280.) That's quite a journey, and more pressingly, quite a variation in temperature. The closer it gets to the Sun, the more debris it sheds. That debris is what you're seeing when you see a meteor shower: dust-sized particles slamming into the Earth's atmosphere at tens of thousands of miles per hour. In a competition between the two, the Earth is going to win, and "shooting stars" are the result of energy released as the particles are vaporized.

The comet was spotted on April 4, 1861 by A.E. Thatcher, an amateur skywatcher in New York City, earning him kudos from the noted astronomer Sir John Herschel. Clues to the comet's discovery are in its astronomical designation, C/1861 G1. The "C" means it's a long-period comet with an orbit of more than 200 years; "G" stands for the first half of April, and the "1" indicates it was the first comet discovered in that timeframe.

Sightings of the Lyrid meteor shower—named after Lyra, the constellation it appears to originate from—are much older; the first record dates to 7th-century BCE China.


Saturday night marks a first quarter Moon (visually half the Moon), which by midnight will have set below the horizon, so it won't wash out the night sky. That's great news—you can expect to see 20 meteors per hour. You're going to need to get away from local light pollution and find truly dark skies, and to completely avoid smartphones, flashlights, car headlights, or dome lights. The goal is to let your eyes adjust totally to the darkness: Find your viewing area, lay out your blanket, lay down, look up, and wait. In an hour, you'll be able to see the night sky with great—and if you've never done this before, surprising—clarity. Don't touch the smartphone or you'll undo all your hard ocular work.

Where is the nearest dark sky to where you live? You can find out on the Dark Site Finder map. And because the shower peaks on a Saturday night, your local astronomy club is very likely going to have an event to celebrate the Lyrids. Looking for a local club? Sky & Telescope has you covered.


You don't need a telescope to see a meteor shower, but if you bring one, aim it south to find Jupiter. It's the bright, unblinking spot in the sky. With a telescope, you should be able to make out its stripes. Those five stars surrounding it are the constellation Libra. You'll notice also four tiny points of light nearby. Those are the Galilean moons: Io, Europa, Ganymede, and Callisto. When Galileo discovered those moons in 1610, he was able to prove the Copernican model of heliocentricity: that the Earth goes around the Sun.


First: Don't panic. The shower peaks on the early morning of the 22nd. But it doesn't end that day. You can try again on the 23rd and 24th, though the numbers of meteors will likely diminish. The Lyrids will be back next year, and the year after, and so on. But if you are eager for another show, on May 6, the Eta Aquariids will be at their strongest. The night sky always delivers.

New NASA Satellite Called TESS Could Discover Thousands of New Planets

Since NASA’s Kepler spacecraft launched in 2009, the space agency has found and confirmed a whopping 2343 new planets. Of those, 30 are considered to be situated in a “habitable zone,” an area in which a planet’s surface could theoretically contain water.

A new satellite, set to launch today, is expected to find thousands more planets outside of our solar system, known as exoplanets. TESS, short for the Transiting Exoplanet Survey Satellite, is NASA’s latest effort to plumb the depths and darkness of outer space in search of other Earth-like planets—including those that could potentially support life.

TESS is slated to complete a two-year survey of the “solar neighborhood,” a general region which comprises more than 200,000 of the brightest nearby stars. To find these outlier planets, NASA scientists will be keeping an eye out for temporary changes in brightness, which indicate that a planet is blocking its host star.

According to Martin Still, the program scientist working on the TESS mission, the launch comes “with certainty” that TESS will find many nearby exoplanets. "We expect to find a whole range of planet sizes, between planets the size of Mercury or even the Moon—our Moon—to planets the same size as Jupiter and everything in between,” Still said in a NASA interview.

While the Kepler mission was considered a major success, NASA noted that most of the planets it recorded are those that orbit faint, faraway stars, making it difficult to conduct follow-up observations. The stars that TESS plans to survey will be 30 to 100 times brighter than those observed by its predecessor. This allows for newly detected planets and their atmospheres to be characterized more easily.

“Before Kepler launched, we didn't know for sure if Earth-sized planets existed,” Elisa V. Quintana, a NASA astrophysicist, told Reddit. “Kepler was a statistical survey that looked at a small patch of sky for four years and taught us that Earths are everywhere. TESS is building on Kepler in the sense that TESS wants to find more small planets but ones that orbit nearby, bright stars. These types of planets that are close to us are much more easy to study, and we can measure their masses from telescopes here on Earth.”

The most common categories of exoplanets are Earth- and Super Earth–sized masses—the latter of which are larger than Earth but smaller than Uranus and Neptune.

TESS is scheduled to launch from the Cape Canaveral Air Force Station in Florida on a SpaceX Falcon 9 rocket at 6:32pm EDT today.

For more information about TESS, check out this video from NASA.


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