Next New Horizons flyby will happen a year from today

View larger. | Artist’s concept of New Horizons’ trajectory, past Pluto, toward 2014 MU69.

One year from today – on January 1, 2019 – the famous Pluto spacecraft called New Horizons will encounter its next target, some billion miles (1.6 billion km) past Pluto, a Kuiper Belt object designated 2014 MU69. New Horizons’ science team has been abuzz since last summer, when the team learned via an occultation of a star by MU69 that this remote and tiny object might be either peanut-shaped or even two objects orbiting one another. In other words, perhaps MU69 is like a binary asteroid (aka an asteroid with a moon).

In December, New Horizons science team member Marc Buie of the Southwest Research Institute in Boulder, Colorado offered an update on scientists’ thoughts about MU69 at the fall meeting of the American Geophysical Union in New Orleans. He said in a statement:

We really won’t know what MU69 looks like until we fly past it, or even gain a full understanding of it until after the encounter. But even from afar, the more we examine it, the more interesting and amazing this little world becomes.

In particular, data collected during a July 10, 2017 occultation of a star by MU69 has led scientists to suspect MU69 might be binary. Scientists were aboard NASA’s airborne Stratospheric Observatory for Infrared Astronomy (SOFIA) – flying over the Pacific Ocean – when they saw what appeared to be a very short drop-out in the star’s light prior to the expected occultation. Buie said further analysis of that data, including syncing it with MU69 orbit calculations provided by the European Space Agency’s Gaia mission, opens the possibility that the “blip” SOFIA detected could be another object orbiting around MU69. Buie commented:

A binary with a smaller moon might also help explain the shifts we see in the position of MU69 during these various occultations. It’s all very suggestive, but another step in our work to get a clear picture of MU69 before New Horizons flies by … a year from now.

Read more about what the occultation data showed, via New Horizons

In 2017, the small Kuiper Belt object 2014 MU69 occulted (briefly hid) 3 faint stars as seen from Earth. Here are the pre-predicted tracks, each only about 30 miles (50 km) wide, from which those disappearances were visible. New Horizons scientists made every effort to observe these occultations, since such events can reveal much about the occulting object. Image via
View larger. | In this image, the colored lines mark the path of the star occulted by 2014 MU69, as seen from different telescopes on different days. The blank spaces on those lines indicate the few seconds when MU69 blocked the light from the star. Graphic via NASA/ Johns Hopkins University Applied Physics Laboratory/ Southwest Research Institute/ James Tuttle Keane/ New Horizons.

By the way, the New Horizons team was looking this past fall for your ideas on an informal name for 2014 MU69. The voting is closed now, but the announcement of the winner is expected soon; it wouldn’t surprise me if it came today. Meanwhile, you can see the 37 names being considered by the team, and see the results of the voting.

At present, Mjölnir – the name of Thor’s hammer in Norse mythology – is leading the pack by a substantial margin. Pronunciation here.

Read more about the voting on a nickname for 2014 MU69

Thus the Kuiper Belt object MU69, discovered as recently as 2014, is poised to become much better known. This object is more than 4 billion miles (6.5 billion km) from Earth. It appears to be no more than 20 miles (30 km) long, or, if a binary, each about 9-12 miles (15-20 km) in diameter.

We live in a wondrous age!

Artist’s concept of NASA’s New Horizons spacecraft streaking past 2014 MU69, which might be 2 objects orbiting each other. Image via Carlos Hernandez/ NASA.

Bottom line: The New Horizons spacecraft will sweep closest to Kuiper Belt object 2014 MU69 one year from today, on January 1, 2019.

January 1, 2018

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Deborah Byrd

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