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dwarf planets, New Horizons mission, planets, Pluto

Pluto Update

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New Horizons on the Approach and a Contest to Name Pluto Surface Features

Is this what Pluto and Charon really look like? We’ll know more as the New Horizons mission gets closer to these distant worlds. Close flyby is set for July 14, 2015.

It’s exciting to think that we are now just a few weeks away from getting some of the first, clearest, and most detailed images of Pluto. The New Horizons mission will soon be close enough to start returning images similar in scope and detail to the first close-up images ever returned of distant worlds when the Voyagers swept past Jupiter, Saturn, Uranus, and Neptune in the late 1970s and 1980s.

Right now, Pluto’s still a large dot in the distance, and the spacecraft has been able to image its small moons Nyx and Hydra. That’s going to get better, of course. I talked with Alan Stern, PI of the New Horizons mission, and as you can imagine, he’s pretty psyched about it, even though the target is still not quite close enough to see good stuff. He’s Pluto Hugger #1, and has dedicated his career to this mission. So, it’s perfectly acceptable to find him excited and bouncing around about what the team will find. “In April, it’ll be a globe to us, and we’ll be about 70 million miles away from it,” he said, pointing out that he and the team have been speculating for years about what they’ll find.

At only a few pixels across in the best Hubble images, Pluto hasn’t been easily giving up its secrets. But, soon New Horizons will show us what it really looks like, and Alan and the team will find out more about the planet’s atmosphere as well as its surface.  “Pluto is a very reflective world—in much the same way fresh snow is,” he said. “We see from Hubble and other images that the surface has markings. Some are red, others are more neutral in color.  We know there’s hydrogen ice there, and methane and ethane, and carbon monoxide ice. How cratered is it? Is there any activity going on there?  What’s the geology of this planet? Those are all questions we’re going to have to wait to answer when New Horizons gets there in July.”

Alan has a fascinating blog on the New Horizons web page called PI’s Perspectives, and he’s been writing all along about the mission, what the team hopes to accomplish, and how the spacecraft works. You can’t get a better look at this last major planetary encounter than through Alan’s eyes, so check it out.

In case you are just starting to follow the New Horizons mission, here are a few facts about it. First, it’s been on the way to Pluto since launch on January 19, 2006. It’s traveling at a velocity (with respect to the Sun) of 14.58 kilometers per second (just over 9 miles per second). It will arrive for a Pluto flyby on July 14, 2015 11:49:57 UTC.

DSN 70-meter dish at Canberra, Australia. Image by Carolyn Collins Petersen. 

Right now, it takes just about 9 hours to send a round-trip message to the spacecraft and back. Mission controllers are communicating with New Horizons through the NASA Deep Space Network station Canberra, Australia, using the 70-meter antenna. You can track New Horizons communications at the Deep Space Network NOW page.

At Pluto, the spacecraft will continue its image- and data-taking routines, snapping images of the surface and moons, and measuring Pluto’s temperature, atmospheric composition, and other characteristics.

Right now (March, 2015) the spacecraft controllers are going through tuning routines for the instruments, and just did a course correction maneuver using an engine burn to fine-tune the spacecraft’s final trajectory toward the Pluto flyby. After it “threads the needle” past the Pluto system, New Horizons heads out further into the Kuiper Belt (a region of space stretching out beyond the orbit of Neptune and populated with many small worlds) and a possible encounter with two more worlds discovered by Hubble Space Telescope in 2014.

Keep an eye out on this little spacecraft that’s about to make some of the biggest discoveries in the outer solar system! The best way to do that is to check the New Horizons page every few days and see what the spacecraft team is doing and finding!

Want to get involved in some cool citizen science at Pluto? The Seti Institute, along with the New Horizons team, is inviting public input on surface feature names for Pluto. The name of the campaign is Our Pluto and the idea is to come up with surface feature names in advance to help the science team out. The campaign runs from now til April 7, so get on over there and contribute to the Pluto naming effort!  Join Alan, and me, and many others in a big “group hug” for Pluto!

 

 

ceres, dawn mission, dwarf planets, planetary science, planets

Ceres Gets a Visitor

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Dawn Mission Achieves First-ever Orbit around a Dwarf Planet

NASA’s Dawn spacecraft has become the first mission to achieve orbit around a dwarf planet. The spacecraft was approximately 38,000 miles (61,000 kilometers) from Ceres when it was captured by the dwarf planet’s gravity at about 4:39 a.m. PST (7:39 a.m. EST) Friday. These images were taken while Dawn was still inbound, on March 1, 2015.

This year is truly the Year of the Dwarf Planet! Earlier today, NASA’s Dawn spacecraft slipped into orbit around dwarf planet Ceres and settled in for a long-term study of this little world. Think about what this achievement means. First, this isn’t the first world the spacecraft has orbited. It also studied the asteroid Vesta for about a year. That makes it the only spacecraft (so far) to orbit two extraterrestrial targets.

Second, it will be the first of two missions this year to give us up-close looks at dwarf planets. The long-awaited New Horizons mission to Pluto and beyond will finally show us some high-resolution details of Pluto, the infamous dwarf planet that is at the heart of so much controversy about what the word “planet” means. I hope for all our sakes that the science we get from these two missions FAR overshadows the controversy. These are worlds. They ARE planets. The term “dwarf” in their  names is not an insult — it’s a descriptor loaded with a LOT of meaning to planetary scientists, who should know what planets are (despite the best efforts of the IAU to dictate to them otherwise). Just as there are types of stars (dwarfs, giants, etc.) and types of galaxies (dwarfs, lenticulars, spirals, etc.), there are types of planets. The cosmos is big enough to contain all the types we want. We just need to recognize that and move on.

Already, Ceres is tantalizing us with a bright spot, a cratered surface, and various other characteristics. This tells ME that this little world, as well as Pluto, has some secrets to share, and that those secrets will enlarge our understanding of the solar system. Knowing our own neighborhood is an important first step toward understanding worlds far beyond our own star, and it helps us “get” where we are in the cosmos. So, stay tuned. Ceres has a lot to show us, and in a few months, Pluto will take its place on center planetary stage and continue the show of a lifetime.