All posts by Tom

Post Pluto


The first of many “post-Pluto” observations from New Horizons. I have to smile because missions like this answer so many questions and ask about twice as many – that’s the fun of science.

From New Horizons:

Warming up for a possible extended mission as it speeds through deep space, NASA’s New Horizons spacecraft has now twice observed 1994 JR1, a 90-mile-wide (145-kilometer-wide) Kuiper Belt object (KBO) orbiting more than 3 billion miles (5 billion kilometers) from the sun. Science team members have used these observations to reveal new facts about this distant remnant of the early solar system.

Taken with the spacecraft’s Long Range Reconnaissance Imager (LORRI) on April 7-8 from a distance of about 69 million miles (111 million kilometers), the images shatter New Horizons’ own record for the closest-ever views of this KBO in November 2015, when New Horizons detected JR1 from 170 million miles (280 million kilometers) away.

Simon Porter, a New Horizons science team member from Southwest Research Institute (SwRI) in Boulder, Colorado, said the observations contain several valuable findings. “Combining the November 2015 and April 2016 observations allows us to pinpoint the location of JR1 to within 1,000 kilometers (about 600 miles), far better than any small KBO,” he said, adding that the more accurate orbit also allows the science team to dispel a theory, suggested several years ago, that JR1 is a quasi-satellite of Pluto.

From the closer vantage point of the April 2016 observations, the team also determined the object’s rotation period, observing the changes in light reflected from JR1’s surface to determine that it rotates once every 5.4 hours (or a JR1 day). “That’s relatively fast for a KBO,” said science team member John Spencer, also from SwRI. “This is all part of the excitement of exploring new places and seeing things never seen before.”

Spencer added that these observations are great practice for possible close-up looks at about 20 more ancient Kuiper Belt objects that may come in the next few years, should NASA approve an extended mission. New Horizons flew through the Pluto system on July 14, 2015, making the first close-up observations of Pluto and its family of five moons. The spacecraft is on course for an ultra-close flyby of another Kuiper Belt object, 2014 MU69, on Jan. 1, 2019.


Prometheus at Work


From JPL:
Most planetary rings appear to be shaped, at least in part, by moons orbiting their planets, but nowhere is that more evident than in Saturn’s F ring. Filled with kinks, jets, strands and gores, the F ring has been sculpted by its two neighboring moons Prometheus (seen here) and Pandora. Even more amazing is the fact that the moons remain hard at work reshaping the ring even today.

Prometheus (53 miles, or 86 kilometers across) shapes the F ring through consistent, repeated gravitational nudges and occasionally enters the ring itself (clearing out material and creating a “gore” feature, see PIA12785). Although the gravitational force of Prometheus is much smaller than that of Saturn, even small nudges can tweak the ring particles’ orbits to create new patterns in the ring.

This view looks toward the sunlit side of the rings from about 12 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 21 2016.

Image and caption: NASA/JPL-Caltech/Space Science Institute

ISS Reaches Historic Milestone!

Congratulations to the International Space Station on completing 100,000 orbits since the station was launched on 20 Nov 1998. In the years since launch the station will have traveled around 2,643,342,240 miles, or roughly the distance between Earth and Neptune.

The event occurred at 06:10 UTC this morning 16 May 2016.


Big Sunspot Coming


Here is an image from the Solar Dynamics Observatory or SDO and we can see a large sunspot on the left side. Actually this sunspot is many-many times the size of Earth and is rotating left to right so in about a week will be directly facing us and that gives us a possibility of increased solar activity including a CME.

I’m not saying anything much will happen, just that the possibility exists – you never know there could be a great aurora coming.

Here are a couple of sites to watch:
Space Weather Prediction Center

MMS Mission Returns Data

We are starting to get data back from the MMS mission.

MMS is made of four identical spacecraft that launched in March 2015. They fly in a pyramid formation to create a full 3-dimensional map of any phenomena it observes. On October 16, 2015, the spacecraft traveled straight through a magnetic reconnection event at the boundary where Earth’s magnetic field bumps up against the sun’s magnetic field.

After more than 4,000 trips though the magnetic boundaries around Earth gathering information about the way the magnetic fields and particles move a surprising result resulted. At the moment of interconnection between the sun’s magnetic field lines and those of Earth the crescents turned abruptly so that the electrons flowed along the field lines. By watching these electron tracers, MMS made the first observation of the predicted breaking and interconnection of magnetic fields in space.

Credit: NASA/GSFC/Genna Duberstein


Mercury Elevation Map

An animation made from data gathered by the MESSENGER spacecraft defining elevation. The topography is colored with higher elevations colored brown, yellow, and red, and regions with lower elevations shown in blue and purple.