Category Archives: New Horizons mission

Kuiper Belt, New Horizons mission

Green Light from the Kuiper Belt

Leave a comment

Moving Toward the Next Kuiper Belt Target

kuiper belt
New Horizons and its trajectory toward its next Kuiper Belt object of study. Courtesy NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Today we got another green light signal from the New Horizons spacecraft. It’s on the way to its second target in the Kuiper Belt, an odd little place called Ultima Thule. A green light means all the boards are good, the mission is still a “go” and the spacecraft is doing its thing.

Kuiper Belt History

Back when I was in graduate school (SO last century!) the Kuiper Belt was just really beginning to be observed by such astronomers as David Jewitt, colleague Jane Luu, self-described “Pluto Killer” Mike Brown, and many others. It was given the name Edgeworth-Kuiper Belt after two planetary astronomers Ken Edgeworth and Gerard Kuiper. They theorized the existence of a region in the outer solar system populated by “leftovers” such as ice-rock worlds and cometary nuclei. In 1987, Jewitt and Luu began looking for such objects and began finding them.

Since that time, others have been found, dubbed KBOs (for “Kuiper Belt Objects”), “Kuiperoids” and “trans-Neptunian Objects”. It happens to be home of Pluto, as well as the dwarf planets Eris, Haumea, Makemake, and Sedna. Ceres, which is also a dwarf planet “lives” in the Asteroid Belt. There are other worlds “out there”. Some are candidates to be defined as dwarf planets at some point. Yet, there are probably many more that haven’t yet been detected. All in all, the Kuiper Belt is a rich treasury of worlds.

In recent times, people studying the dynamics of comets have come to realize it’s not the home of all short-period comets. They largely come from a “scattered disk” of nuclei that are associated with the Belt. So, there’s a lot more work to be done to understand and chart this distant realm of the solar system.

What’s Coming up Next

In a few months, New Horizons (currently sleeping its way to Ultima Thule) will wake up. That will happen in July. After that, it will be all hands on deck as the spacecraft gets closer. At that time, the cameras and other sensors will do their thing on the way to a late December 2018 encounter.

In the meantime, scientists are still analyzing the Pluto data. They’re also touting images the spacecraft took during its last “waking period” in December 2018. They weren’t of a planet, but rather of a star cluster about 1,300 light-years from Earth. While it’s not the best imagery of the cluster, it is the first imagery from such a great distance from the Sun. Not only did New Horizons snap that image, but it also got pictures of two other Kuiper Belt objects. The spacecraft will take images of as many KBOs as it can, adding to our store of knowledge about this distant region.

New Horizons mission, Ultima Thule

New Horizons’ Next Target Has a Nickname: Ultima Thule

Leave a comment

On the Way to Ultima Thule

Ultima Thule
Artist’s impression of NASA’s New Horizons spacecraft encountering 2014 MU69, a Kuiper Belt object that orbits one billion miles (1.6 billion kilometers) beyond Pluto, on Jan. 1, 2019. Credit: NASA/JHUAPL/SwRI/Steve Gribben

All these years since its discovery, the little world 2014 MU69 hasn’t had a nickname until now. NASA announced a contest to name this next target for New Horizons. After months of entries and deliberation, the winning name is “Ultima Thule”. For those of us who live in the toolies here on Earth, it’s a great name. It definitely reflects its distance out in the solar system. And, with this week’s “green light” from the spacecraft headed toward Ultima, it’s nice to have a colorful name to hang on this still-mysterious world.

I was beginning to wonder what the contest had selected. Of course, I kept asking Alan Stern about it, and he kept being perfectly mysterious about the whole thing. Now that the nickname is public, it’ll go to the IAU for final approval. Its job is to make sure the name fits, which should be easy for that organization to figure out.  It’s perfectly appropriate, as Alan pointed out in the NASA announcement about Ultima, “MU69 is humanity’s next Ultima Thule,” he said. “Our spacecraft is heading beyond the limits of the known worlds, to what will be this mission’s next achievement. Since this will be the farthest exploration of any object in space in history, I like to call our flyby target Ultima, for short, symbolizing this ultimate exploration by NASA and our team.”

I like the name, too. It sounds all science-fictiony. In fact, that name has been used in science fiction stories as a sort of “ultimate” destination among the stars.

What IS This Tiny World?

Nobody’s quite sure exactly how Ultima Thule looks. The image up there is a “best guess”. That’s because the spacecraft is still too far to get a detailed image of it. Ground-based observations seem to indicate it might be a double-lobed potato-shape world. Or, it might be what they call a “contact binary”. That’s two pieces of worlds in very close proximity to each other. One way or another, once New Horizons gets closer, it will solve the mystery and show us this next outpost in the Kuiper Belt.