dwarf planets – Page 3

Enigmatic Pluto emits x-rays and ‘spray-paints’ its largest moon, new research shows

September 19, 2016 by Paul Scott Anderson

For the first time, x-rays have been detected around Pluto, as seen by Chandra (inset image). Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Chandra X-Ray Center

It has been 14 months since the New Horizons spacecraft flew past Pluto and its moons, but data still continues to come in, and new discoveries are still being made. The dwarf planet has surprised scientists by its geological activity, for the most part unexpected for such a small, cold body. Now two new results are adding to the mystery of Pluto: the detection of x-rays emanating from the surface and new evidence that Pluto “spray-paints” the north pole of its largest moon Charon a rusty red colour.

Pluto revealed: Five new Science papers highlight discoveries by New Horizons

March 23, 2016 by Paul Scott Anderson

High-resolution view of Pluto from New Horizons. The large smoother area of ice in Sputnik Planum is the western lobe of the “heart” feature. Image Credit: NASA/JHUAPL/SwRI

Pluto is a tiny world in the outer fringes of the Solar System; for many decades it was only a mere speck of light in even the best telescopes, with only vague hints of surface features. Then, in July 2015, the New Horizons spacecraft flew past Pluto, the first time ever that humanity would get to see this mysterious place up close – and it did not disappoint. An enormous amount of data has continued to be sent back by New Horizons since the flyby, and now five new papers have been published which provide an in-depth overview of the findings so far about Pluto and its moons. Pluto is an active world, with its own unique geology different from anywhere else in the Solar System.

Dawn celebrates one year at Ceres with incredible new images of ‘Lonely Mountain’

March 9, 2016 by Paul Scott Anderson

View of Ahuna Mons from the low-altitude mapping orbit (LAMO). Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

It has been a year now since the Dawn spacecraft first reached the dwarf planet Ceres in the main asteroid belt between Mars and Jupiter, and during that time has shown Ceres to be a unique and complex little world. At first glance, Ceres just seems to be a heavily battered place, covered in craters like the Moon or Mercury, but a closer look reveals something more interesting: a small rocky world with large fractures, unusual “bright spots” randomly dispersed across the surface and an odd conical “mountain” which sits in isolation with nothing else like it around. Dawn has already acquired an enormous amount of data about Ceres, but now, in its lowest possible orbit, will continue to do for some time to come.

New Horizons discovers methane ‘snow’ on Pluto’s mountain peaks

March 8, 2016 by Paul Scott Anderson

Methane “snow” on mountain peaks in the Cthulhu region of Pluto. The enhanced colour version of the inset image is on the left and the false colour version is on the right. The image covers an area 450 kilometres (280 miles) long by 225 kilometres (140 miles) wide. Image Credit: NASA/JHUAPL/SwRI

As the data from New Horizons continues to come in, we are learning more about what an incredible little world Pluto really is, with tall mountains of rock-hard water ice, as well as glaciers and vast icy plains composed of nitrogen ice. In some ways, these features are visually reminiscent of similar ones on Earth, and now this week another cool discovery was revealed: methane snow on some of Pluto’s mountain peaks.

New Horizons finds evidence for frozen ocean inside Pluto’s moon Charon

February 22, 2016 by Paul Scott Anderson

The canyons of Charon, some of which dwarf the Grand Canyon on Earth. Image Credit: NASA/JHUAPL/SwRI

One of the most surprising discoveries in recent years in the outer Solar System is that there are small moons which have oceans inside them. Jupiter’s moon Europa and Saturn’s moon Enceladus are now known to have global oceans of water beneath their icy crusts, and others are thought to as well, including Ganymede, Titan, and possibly others. These moons have a lot of ice and rock as well, and gravitational tugging and heating from the large gas giant planets helps maintain a deep layer of liquid water inside them, where otherwise they would most likely be frozen solid in the deep cold so far from the Sun. Now it seems that another moon also once had an ocean, although in this case it is thought to now be solid ice: Pluto’s largest moon, Charon.

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