New Horizons flies by distant planetoid

[lpetrich]

A little after midnight US Eastern Standard Time, New Year's Day 2019, the  New Horizons spacecraft flew by a small planetoid. It was discovered in a search for places for NH to visit after Pluto. It was first called 2014 MU69, then Minor Planet 486958. It has recently been nicknamed Ultima Thule, from a term in antiquity for far-north lands ( Thule).

New Horizons scientists elated as Ultima Thule’s shape comes into view – Spaceflight Now
New Horizons: Ultima Thule Encounter

Finding the shape of 2014 MU69 from occultations | The Planetary Society  (486958) 2014 MU69 These eclipses of stars revealed that this object is either two objects orbiting close together or touching each other.

The first pictures sent back from NH that resolve this object indeed confirm this impression -- it looked elongated and dumbbell-ish. But they are only a few pixels across and we must await NH sending back more detailed pictures. But it is enough to give the object's overall size: 35 km * 15 km (21 mi * 9 mi).

The spacecraft will upload some more pictures over the next few days, before having to interrupt its upload because the Sun will be too near its line of sight from the Earth. But it should restart in the middle of this month and continue for the next 20 months, much as it had done with Pluto.

After that, NH might be aimed at some more distant Kuiper Belt Object.

 

[lpetrich]

NASA's New Horizons Mission Reveals Entirely New Kind of World shows a higher-resolution picture.

The new images — taken from as close as 17,000 miles (27,000 kilometers) on approach — revealed Ultima Thule as a "contact binary," consisting of two connected spheres. End to end, the world measures 19 miles (31 kilometers) in length. The team has dubbed the larger sphere "Ultima" (12 miles/19 kilometers across) and the smaller sphere "Thule" (9 miles/14 kilometers across).

The page shows a high-resolution grayscale picture, a lower-resolution color picture, and a combined one. Described as reddish, it looks brown to me.

They are still not sure what the object's rotation period is, though with more detailed pictures, it may soon be possible to tell.

 

[4321lynx]

NASA's New Horizons Mission Reveals Entirely New Kind of World shows a higher-resolution picture.

The new images — taken from as close as 17,000 miles (27,000 kilometers) on approach — revealed Ultima Thule as a "contact binary," consisting of two connected spheres. End to end, the world measures 19 miles (31 kilometers) in length. The team has dubbed the larger sphere "Ultima" (12 miles/19 kilometers across) and the smaller sphere "Thule" (9 miles/14 kilometers across).

The page shows a high-resolution grayscale picture, a lower-resolution color picture, and a combined one. Described as reddish, it looks brown to me.

They are still not sure what the object's rotation period is, though with more detailed pictures, it may soon be possible to tell.

It's a golden-coloured Snowman!!!

 

[lpetrich]

Ultima Thule emerges as contact binary, "cosmic snowman," in new spacecraft images | Astronomy.com

Its rotation period is 15 +- 1 hours, and its spin axis is perpendicular to its long axis, as one would expect.

Scientists can also now infer some geological properties of Ultima Thule. The body has a mottled appearance due to some surface irregularities or differences in elevation. It appears not to have any impact craters. It does show the tight, squeezed area of a belt, the small region where the two lobes are in contact. It has some brighter regions, and some darker ones. We’ll continue to learn much more about the object’s geology in the coming hours and days.

 

[repoman]

So that picture was taken from 28,000 km and it got as close at 3,500 km. I am not sure where the pictures were taken on the trajectory.

 

[Jimmy Higgins]

NASA's New Horizons Mission Reveals Entirely New Kind of World shows a higher-resolution picture.

The new images — taken from as close as 17,000 miles (27,000 kilometers) on approach — revealed Ultima Thule as a "contact binary," consisting of two connected spheres. End to end, the world measures 19 miles (31 kilometers) in length. The team has dubbed the larger sphere "Ultima" (12 miles/19 kilometers across) and the smaller sphere "Thule" (9 miles/14 kilometers across).

The page shows a high-resolution grayscale picture, a lower-resolution color picture, and a combined one. Described as reddish, it looks brown to me.

They are still not sure what the object's rotation period is, though with more detailed pictures, it may soon be possible to tell.

It's a golden-coloured Snowman!!!

Pfft! It is BB-8, someone has clearly has hacked the data. [emoji6]

 

[lpetrich]

The spacecraft reached 3,500 km / 2,200 mi from the planetoid, and it was traveling at 51,500 km/h / 32,000 mph relative to it, 14.3 km/s.

It thus traveled its minimum distance in about 4 minutes.

That recent and detailed image was taken about 30 minutes before closest approach -- it was around 28,000 km / 17,000 mi away.

 

[Shake]

Here's the image from today's APOD post:

 

[Treedbear]

A great show about this on PBS Nova last night. Including the first few pictures so was very current. Included the fantastic story of how the object was identified as well as the complex steps needed to determine its path. Truly amazing science. Also some nice images of Pluto and history about why it was reclassiified.

 

[repoman]

Has there been any interesting data yet other than pictures? Hard to know where to look for it.

 

[Angry Floof]

Ultima Thule totally sounds like a Star Trek name. She's probably bffs with Una Carapledes.

 

[barbos]

Here's the image from today's APOD post:

better picture:

 

[lpetrich]

New Horizons: 2019 Onward

There is more to come. New Horizons will be uploading its pictures of Ultima Thule until late summer next year, much as it took over a year to upload its pictures of Pluto and its moons.

The spacecraft may look at other Kuiper Belt Objects, even if it is not aimed at any one of them for a flyby, and it will continue to sample the space environment. It is funded until at least 2021.