Jupiter’s Atmosphere is Surprisingly Hot

Temperature measurements of Jupiter's upper atmosphere. Credit: James O’Donoghue

Jupiter is a big planet, but it’s still a planet. That means it doesn’t heat itself through fancy mechanisms like nuclear fusion. Its interior is heated through its own weight, squeezing the interior through hydrostatic equilibrium, and its surface is heated mostly by the Sun. Since Jupiter only gets about 4% of the light per square meter that Earth gets, you’d expect its upper atmosphere to be pretty cold. Traditional models estimate it should be about -70 degrees Celsius. But recent measurements show the upper atmosphere is over 400 degrees Celsius, and in the polar regions as much as 700 degrees Celsius. In the words of Ruby Rhod from the movie The Fifth Element, “It’s Hot Hot Hot!”

Continue reading “Jupiter’s Atmosphere is Surprisingly Hot”

A New Map Shows how Solar Winds Rain Down Everywhere on Mars

In a joint effort between NASA’s MAVEN spacecraft and the United Arab Emirates’ Emirates Mars mission (EMM), scientists have observed an uncommonly chaotic interaction between the solar wind and Mars’ upper atmosphere, creating a unique ultraviolet aurora. The phenomenon represents an unusual occurrence in Martian space weather, and scientists are excited to take advantage of future collaborations between spacecraft to keep an eye out for repeat events.

Continue reading “A New Map Shows how Solar Winds Rain Down Everywhere on Mars”

Webb Telescope Sees Jupiter and Its Auroras in a New Light

JWST view of Jupiter
The James Webb Space Telescope's NIRCam imager produced this composite image of the Jupiter system using orange and cyan filters. The image shows Jupiter's auroras as bright rims at the poles. The planet's rings and two of its moons, Amalthea and Adrastea, are also visible. Credit: NASA, ESA, CSA, Jupiter ERS Team; image processing by Ricardo Hueso (UPV/EHU) and Judy Schmidt.

NASA’s James Webb Space Telescope is designed to probe the farthest frontiers of the universe, but newly released images of Jupiter prove that the observatory can also bring fresh perspectives to more familiar celestial sights.

The infrared images reveal Jupiter’s polar auroras and its faint rings as well as two of its moons — plus some galaxies in the far background. The planet’s Great Red Spot is there as well, but because it’s seen through three of JWST’s specialized filters, it looks white rather than red.

JWST’s new perspective should give scientists a better sense of how the complex Jupiter system is put together.

Continue reading “Webb Telescope Sees Jupiter and Its Auroras in a New Light”

Chinese Astronomers Recorded Earliest Account of Aurora

How dating an ancient text revealed one of the oldest observations of aurora known.

It’s one of the greatest sky spectacles you can witness. Along with a total solar eclipse and a major meteor storm, I’d put a fine aurora display up there as one of the the most amazing things you can see in the night sky. And we’re not talking about the dull green glow that folks in the ‘lower 48’ see to the north and dismiss, but the glorious silent streamers of auroral curtains that can light up the entire sky.

Now, a recent study, entitled A Candidate Auroral Report in the Bamboo Annals Indicating a Possible Extreme Space Weather Event in the 10th Century BCE may have pinpointed one of the earliest accounts on ancient aurorae. In the study, University of Pennsylvania and Nagoya University researchers culled through the legendary chronicle known as the Bamboo Annals (also sometimes referred to as Zhushu Jinian) penned around the 4th century BCE. Chinese texts are some of the best documented sources of sky phenomena stretching back over the millennia, to include accounts of naked eye sunspots, supernovae and meteor outbursts.

Continue reading “Chinese Astronomers Recorded Earliest Account of Aurora”

Here’s the View From Sweden During the Recent Solar Storm

Aurora seen in Sweden, October 12, 2021. Credit: All-sky camera, Kiruna Atmospheric and Geophysical Observatory (KAGO) within the Swedish Institute of Space Physics (IRF).

Vivid green and purple aurora swirled and danced across the entire night sky in Sweden recently. The nighttime light show was captured by an all-sky camera in Kiruna, Sweden, which is part of the European Space Agency’s (ESA) Space Weather Service Network.

Continue reading “Here’s the View From Sweden During the Recent Solar Storm”

Ions Surf Through Jupiter’s Magnetic Field, Triggering its Auroras

Auroras come in many shapes and sizes.  Jupiter is well known for its spectacular complement of bright polar lights, which also have the distinction of appearing in the X-ray band.  These auroras are also extreme power sources, emitting almost a gigawatt of energy in a few minutes. But what exactly causes them has been a mystery for the last 40 years.  Now, a team used data from a combination of satellites to identify what is causing these powerful emissions.  The answer appears to be charged ions surfing on a kind of wave.

Continue reading “Ions Surf Through Jupiter’s Magnetic Field, Triggering its Auroras”

Uranus X-Rays are Probably Reflected Sunlight, but There Could be Another Source as Well

X-rays offer a unique insight into the astronomical world.  Invisible to the naked eye, most commonly they are thought of as the semi-dangerous source of medical scans.  However, X-ray observatories, like the Chandra X-ray Observatory are capable of seeing astronomical features that no other telescope can.  Recently scientists found some of those X-rays coming from a relatively unexpected source – Uranus.

Continue reading “Uranus X-Rays are Probably Reflected Sunlight, but There Could be Another Source as Well”

Brown dwarf discovered with a radio telescope for the first time

Artist view of a cool brown dwarf. Credit: ASTRON / Danielle Futselaar

Brown dwarfs are interesting objects. They are generally defined as bodies massive enough to trigger the fusion of deuterium or lithium in their cores (and are thus not a planet) but too small to fuse hydrogen in their cores (and therefore not a star). They are the middle children of cosmic bodies.

Continue reading “Brown dwarf discovered with a radio telescope for the first time”

Even Comets Can Have Auroras. Comet 67P/Churyumov-Gerasimenko Does

Data from Southwest Research Institute-led instruments aboard ESA’s Rosetta spacecraft helped reveal unique ultraviolet auroral emissions around irregularly shaped Comet 67P. Although these auroras are outside the visible spectra, other auroras have been seen at various planets and moons in our solar system and even around a distant star. Image Credit: ESA/Rosetta/NAVCAM

The ESA’s Rosetta mission to Comet 67P/Churyumov-Gerasimenko ended four years ago. On September 30th 2016 the spacecraft was directed into a controlled impact with the comet, putting an end to its 12.5 year mission. Scientists are still working with all its data and making new discoveries.

A new study based on Rosetta data shows that Comet 67P has its own aurora.

Continue reading “Even Comets Can Have Auroras. Comet 67P/Churyumov-Gerasimenko Does”

Time-Lapse Video Reveals 10 Years of the Sun’s Life Crushed into One Stellar Hour

A still shot of the SDO time-lapse

I forget the Sun is a star.

I think we all do sometimes. It’s easy to take for granted. The Sun is that glowing thing that rises in the morning and sets in the evening that we don’t generally pay attention to as we go about our day. However, there are these rare moments when we’re reminded that the Sun is truly a STAR – a titanic living sphere of hydrogen smashing plasma a million times the volume of Earth. One of those rare moments for me was standing in the shadow of the 2017 solar eclipse. We had driven down from Vancouver to Madras, Oregon to watch this astronomical freak of nature. A moon hundreds of times smaller than the Sun, but hundreds of times closer, covers the face of the Sun for the majesty of a STAR to be revealed; the fiery maelstrom of the Sun’s atmosphere visible to the naked eye.

Matt Eclipse 2.jpg
Sun’s corona visible to the naked eye in the shadow of the Moon during the 2017 Solar Eclipse as seen from Madras, Oregon c. Paul Muzzin / Matthew Cimone
Continue reading “Time-Lapse Video Reveals 10 Years of the Sun’s Life Crushed into One Stellar Hour”