New Horizons probe on course for historic flyby

Artist’s concept of the New Horizons spacecraft flying by a possible binary 2014 MU69 (Ultima Thule) This New Year's Eve. Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

NASA's New Horizons probe remains on course for its flyby of Ultima Thule, an object which is 30km wide, that will occur on New Year's Day at a distance of 6.5 billion km from Earth, when the daring spacecraft travelling at 51,000km/h. will encounter this object three year after its main goal at Pluto. 

This far away world of our Solar System is on part of the Kuiper Belt, New Horizon will pass at a distance of 3,500km from icy Ultima's surface taking a series of photos and other data. There is also the concern that the object could be surrounded by large debris particles which could result in the destruction of the probe, however it appears to be safe. 

What is known about Ultima Thule? 

Not much. A world discovered only four years ago by the Hubble telescope when searching for potential targets that New Horizons could visit after its Pluto encounter. it was originally known as (486958) 2014 MU69, and later given is current denomination of Ultima Thule (Pronounced: Tool-ee). 

It is likely to be composed of dust and ices like many of Kuiper belt objects of its type, which came together at the dawn of the Solar System more than 4.5 billion years ago. In theory this objects bodies will take on an elongated shape, but that will be known soon enough. Also it may have a dark surface having being "burnt" through the eons du to high-energy radiation such as cosmic rays and X-rays. 

Artwork: scientists can only speculatate of what Ultima Thule looks like. Credit: NASA

Illustration of NASA’s New Horizons spacecraft encountering 2014 MU69 – nicknamed “Ultima Thule” – a Kuiper Belt object that orbits one billion miles beyond Pluto. Set for New Year’s 2019, New Horizons’ exploration of Ultima will be the farthest space probe flyby in history. Credits: NASA/JHUAPL/SwRI

Scientists are hoping that Ultima Thule will help prove that this type of bodies of our Solar System grew from the mass accretion of a great many pebble-sized grains. 

Although New Horizons has already spotted something peculiar about Ultima, and that is the lack of a light curve. Scientists were expecting to see repeated pulsations in brightness from a rotating object of an elongated shape, they refer to this as a light curve. 

Marc Buie, of the Southwest Research Institute says “It’s possible that Ultima’s rotation pole is aimed right at or close to the spacecraft,” SETI Institute’s Mark Showalter says that “Another explanation is that Ultima may be surrounded by a cloud of dust that obscures its light curve, much the way a comet’s coma often overwhelms the light reflected by its central nucleus.” And “an even more bizarre scenario is one in which Ultima is surrounded by many tiny tumbling moons,” says Anne Verbiscer from the University of Virginia. 

What is expect from this flyby? 

It will be fast. Unlike the flyby with Pluto back in July of 2015, there will not be time for increasingly resolved images while the approaching its taking place, Ultima won’t be very much resolved on the viewfinder until very close to its encounter time, that is 05:33 GMT. However, the distance from Pluto and New Horizon was 12,500 km and with Ultima will be 3,500 km, so more detail may be observed. 

Also New Horizon cannot keep its antenna locked on Earth while also gathering data. So controllers must therefore wait until later on New Year's Day for the probe to "phone home" call and to star to download some images, which will happen between January 3 and 3 before we get a good image. 

After taking hundreds of images of Ultima Thule (yellow dot), mission planners are confident there is little debris close to the object and it is safe to stay on the inner path (3,500km flyby distance) as opposed to the outer trajectory (10,000km) Credit: NASA/JH-APL/SWRI

What happens after with New Horizons? 

The team is hoping to get an extended mission fund from NASA, altering it course to at least visit one more one more Kuiper belt object sometime in the next decade, since it has enough fuel to this. Also its plutonium battery may even allow New Horizon to keep talking to Earth as it leaves the Solar System, both Voyager missions have now exited the heliosphere, that occurred at around 119 Astronomical Units. At the moment New Horizon is at 44 AU and racing at about 3 additional AU per year, Alan Stern said that its power system could probably run to about 100 AU, so there is the hope for more science after this mission. 

Both Voyager probes are now outside the heliosphere. Credit: NASA

This image shows New Horizons' current position along its full planned trajectory. The green segment of the line shows where New Horizons has traveled since launch; the red indicates the spacecraft's future path. Positions of stars with magnitude 12 or brighter are shown from this perspective, which is above the Sun and "north" of Earth's orbit. Credit: NASA

Source: NASA, All About Space, BBC,