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Archive for the ‘Kuiper Belt Objects’ Category

02/12/2018 – Ephemeris – Ultima Thule is not what it first seemed

February 12, 2019 Comments off

Ephemeris for Tuesday, February 12th. Today the Sun will be up for 10 hours and 18 minutes, setting at 6:06, and it will rise tomorrow at 7:46. The Moon, at first quarter today, will set at 2:03 tomorrow morning.

This is just nuts. When the New Horizons spacecraft got around behind the body nicknamed Ultima Thule New Years Day and took a crescent view of it, they got a much thinner crescent than they thought. Instead of two round balls in contact, that they saw on approach they saw two very flattened lumps. From the approach side the body looked like a small ball sitting on a larger one. It turns out that the two components of Ultima Thule, named Ultima for the part with the greater diameter and Thule the smaller actually have the same mass. The spin axis runs right through the narrow neck that connects them. That’s their center of mass, or center of gravity. It’s sending planetary scientists back to the blackboard.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

First closeup of Ultima Thule

Ultima Thule on approach combining low resolution color image with the high-resolution monochromatic image shows the body in almost true color. Credit NASA/JHUAPL/SwRI.

Crescent Ultima Thule

The crescent of Ultima Thule, looking back after closest approach. Credit NASA/JHUAPL/SwRI.

Possible side view of Ultima Thule

Side view of Ultima Thule: Top as it was from the approach images. Bottoms as it actually appears to be. The blue dash lines the limits of what the flattening could be. Credit NASA/JHUAPL/SwRI.

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01/14/2019 – Ephemeris – New Horizons returned first images of Ultima Thule

January 14, 2019 1 comment

Ephemeris for Monday, January 14th. The Sun will rise at 8:17. It’ll be up for 9 hours and 9 minutes, setting at 5:26. The Moon, at first quarter today, will set at 2:04 tomorrow morning.

On January 1st, just after midnight eastern time the New Horizons spacecraft made its closest pass of the small Kuiper Belt Object 2014 Mu69, nicknamed Ultima Thule. At just about 10:30 that morning the expected phone home came back over 4 billion miles, and 6 hours travel time from a 15 watt transmitter on the spacecraft. New Horizons was in perfect health an its data recorders were full. It will take 20 months at a thousand bits per second to relay all that information back to Earth. Though we’ll get better pictures to come, Ultima Thule is a contact binary of two nearly spherical bodies that collided very gently. It looks like a snowman of reddish-brown snow. It fits the silhouette made by it passing in front of a star back in 2017.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

First closeup of Ultima Thule

Ultima Thule on approach combing a low resolution color image with the high resolution monochromatic image shows the body in almost true color. Credit NASA/JHUAPL/SwRI

Occultation

Pre-encounter occultation attempts of Ultima Thule. Continued caption from the Vatican Observatory Foundation Blog: “The colored lines mark the path of a star as seen from different telescopes on each day; the blank spaces on those lines indicate the few seconds when MU69 blocked the light from the star. Credit: NASA / JHUAPL / SwRI / James Tuttle Keane”

Note from the image:  The term “astrometry” (pronounced as-trom-e-try) is the science of measuring the precise positions and motions of celestial bodies.

The New Horizons spacecraft went into solar conjunction from January 4th to the 9th.  Meaning it was too close to the direction of the Sun to send of receive data due to the Sun’s radio interference.  On the night of the 9th I noticed that on the DNS-Now website that the big antenna at Canberra Australia was in contact with it.  So more data is flowing down!

01/26/2016 – Ephemeris – Planet X

January 26, 2016 Comments off

Ephemeris for Tuesday, January 26th.  The Sun will rise at 8:08.  It’ll be up for 9 hours and 33 minutes, setting at 5:42.   The Moon, 3 days past full, will rise at 8:44 this evening.

Last week Dr. Mike Brown and Konstantin Batygin announced that they have good cause to suspect that there is a Neptune sized planet lurking in the outer Kuiper Belt,  perhaps 1,000 AU or a 1,000 times the Earth’s distance from the sun.  In miles that comes to a possible distance of 100 billion miles from the sun. The evidence is the odd similarity of the orbits of six Kuiper belt objects, including the best known Sedna, whose closest points of their orbits to the Sun, called perihelia are remarkably close together.  Planet X is not a name, but a placeholder for something unknown, like X in an equation, which will be replaced by a real designation if found and confirmed.  So no, Planet X has not been found, but as Sherlock Holmes would say: the game is afoot.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Suspected Planet X Orbit

The obit off to the right is the suspected orbit of the unknown body dubbed Planet X or Planet 9. Credit: Mike Brown and Konstantin Batygin.

Links to explore this further from reliable sources are:  Universe TodayThe Planetary Society, and Phil Plait’s Bad Astronomy.