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Moving Toward the Next Kuiper Belt Target

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.

The Coming Demise of Tiangong-1

The world is watching during the final days and hours of the Tiangong-1 space station’s life. We’re all waiting to see where it will finally fall. The station put into orbit by the Chinese space agency in 2011, is slowly losing altitude as it circles Earth. The best predictions (from such places as Aerospace.org) suggest it will make a blazing re-entry into Earth’s atmosphere around 4:305 UTC on April 1. The margin of error is plus or minus 24 hours. Realistically, that means it will re-enter anytime from 4:30 UTC on the 30th to the same time on the 2nd of April.

Predicting where Tiangong-1’s pieces will impact the planet is difficult. Based on its orbit and where it will start to break up, experts are saying that it could fall to Earth along a fairly long orbital track. It could be anywhere from about 42 degrees north latitude to about 42 degrees south latitude. Since a large fraction of Earth’s surface is covered with water, it’s very likely most (if not all) pieces will end up in an ocean. However, they could also strike land. To find out more, including the possibilities for seeing its re-entry, your best bet is to watch the Aerospace.org page above and keep an eye on such pages as Space.com and SkyandTelescope.com. Another good source is Heavens Above. You can localize it to your spot on Earth.

What is Tiangong-1?

The Chinese space agency’s Tiangong-1 is a habitable, but empty, space station. It was launched in September 2011 and used for about four years. The last astronaut mission was in 2013. The lab stopped communicating with Earth stations in 2016. The agency is claiming its re-entry will be a controlled de-orbit, although it’s still very difficult to difficult to predict where it will enter. This is partly due to conditions in the upper atmosphere and unknowns about when the spacecraft will encounter a higher drag, which will slow it down enough to re-enter.

Quick Look: The Chinese Space Effort

The Chinese National Space Administration is the main institution responsible for Tiangong-1 and other space exploration activities in China. It formed in 1993 as part of two restructurings of Chinese space companies and institutions. CNSA has cooperative agreements with a number of other space agencies, including the European Space Agency and to some extent. It does have some cooperation with US entities. However, there is still a ban on US researchers working with Chinese researchers in space exploration.

CSNA has a corps of ten “taikonauts” and is divided into four main departments covering planning, engineering, science and technology, and foreign affairs. You can read a reasonably up-to-date description of the program here and visit the agency’s Web page for current events.

Currently, CNSA is moving toward exploration of the Moon and Mars in the next decade. The agency also has lofted a second Tiangong station into Earth orbit. It is developing more heavy-lift rocket capability, and it has sent several crewed missions to space.

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Green Light from the Kuiper Belt