Looking at Mars at Night in UV

This obviously false color animation of Mars shows how its atmosphere glows and pulsates in ultraviolet light every night. It was assembled from months of data taken by the MAVEN spacecraft orbiting Mars. The nightglows occur three times during each rotation of the planet about 70 km above the surface. All three occur at sunset (which is on the left limb of the planet in this view). The pulsations are believed to be caused by downward winds creating nitric oxide in the atmosphere which glows in the UV spectrum. The fact that the three glows occur in data averaged over several months indicates that they are a nightly occurrence.

Video Credit: NASA

A Galaxy and a Star

This image taken by the Hubble Space Telescope show a galaxy cataloged as NGC 4907. Its about 270 million light-years away. The bright star in the image below the galaxy is in our galaxy. It appears to outshine the billions of stars in NGC 4907 because it is roughly 100,000 time closer to us.

Image Credit: NASA / ESA

This is Named for a Distant Cousin

hoag_hubble_960Is this one galaxy or two? That question came up back in 1950 when astronomer Art Hoag (a very distant relative) found this unusual extragalactic object. The ring full of bright blue stars surrounds a center of older, redder stars. The gap appears almost completely dark. How Hoag’s Object formed is unknown, but similar objects have now been identified and collectively labeled as a form of ring galaxy. Best guesses include a galaxy collision billions of years ago and the gravitational effect of a central bar that has since vanished. This photo was taken by the Hubble Space Telescope in 2001 and shows unprecedented details of Hoag’s Object. It spans about 100,000 light years and is around 600 million light years away toward the constellation of the Serpens (the Snake). Another ring galaxy is visible in the gap (at about one o’clock).

Image Credit: NASA

A 3D Model of the Helix Nebula

The Helix Nebula (aka NGC 7293) is a large planetary nebula located in the constellation Aquarius. It’s about 700 light-years away. The Helix Nebula has sometimes been referred to as the “Eye of God.” Tolkien fans have occasionally called it the “Eye of Sauron”

This animation of a 3-D model was created from Hubble Space Telescope and ground-based data of the Helix Nebula.

Credit: NASA, ESA, and G. Bacon (STScI)

Ganymede’s North Pole

On 26 December, 2019, the Juno spacecraft’s orbit around Jupiter brought it near the north pole of the ninth-largest object in the solar system, the moon Ganymede. The spacecraft’s Jovian Infrared Auroral Mapper (JIRAM) instrument took the first infrared images of the massive moon’s north pole.

Ganymede only moon in the solar system that is larger than the planet Mercury. It’s mostly water ice. It is also the only moon in the solar system with its own magnetic field. On Earth, the magnetic field provides a pathway for plasma (charged particles from the Sun) to enter our atmosphere and create aurora. Ganymede has no atmosphere to impede the progress of those charged particle, so the surface at its poles is constantly being bombarded by plasma from Jupiter’s gigantic magnetosphere. The bombardment has a dramatic effect on Ganymede’s ice.

The ice near both poles of the moon is amorphous. This is cause by the impact of the plasma on the surface. That pounding prevents the ice from having a crystalline structure.

Image Credit: NASA/ JPL / SWRI / ASI / INAF

The Crab’s Neutron Star

Heart of the CrabThis Hubble image peers deep into the core of the Crab Nebula, revealing its beating heart. At its center are the remnants of a supernova which sends out clock-like pulses of radiation and waves of charged particles. The neutron star at the very center of the Crab Nebula has about the same mass as the Sun, but it’s compressed into an incredibly dense sphere that is only a few miles across. Spinning 30 times a second, the neutron star ticks along, shooting out detectable beams of energy.

Image Credit: NASA / ESA

The Far Side

FarSideUVThe STEREO (Solar TErrestrial RElations Observatory) mission used a pair of spacecraft launched into orbit around the Sun. One slowly moved ahead of the Earth, and the other slowly lagged behind. Their separation allowed for simultaneous stereoscopic images to be taken of the Sun. The lagging spacecraft failed in 2014, but the leading spacecraft is still operational. This picture of the Sun was taken with the Extreme Ultraviolet Imager onboard the Solar TErrestrial RElations Observatory Ahead (STEREO-A) spacecraft. The spacecraft collects images in several wavelengths of light that are invisible to the human eye. This image shows the sun at a wavelength of 17.1 nm which which is usually coded in blue for false color imaging. STEREO-A is out of communication with the Earth when it’s on the far side of the Sun, where it operates in safe mode, collecting and saving data from its instruments. This image was taken by STEREO-A in July, 2015, from a point of view on the far side of the solar system as it had moved far enough around in its orbit to regain contact with the Earth.

Image Credit: NASA

NASA/ESA Release the First Images from the Solar Orbiter

This animation shows a series of views of the Sun captured by Extreme Ultraviolet Imager on the Solar Orbiter on 30 May. They show the Sun’s appearance at a wavelength of 17 nanometers in the extreme ultraviolet region of the electromagnetic spectrum. Images at this wavelength allow examination of the Sun’s upper atmosphere and the corona, regions with temperatures of more than 1,000,000 C.

A Close Up View of a Comet

This picture, assembled from data from the WISPR instrument on the Parker Solar Probe, shows the twin tails of Comet NEOWISE as seen on 5 July, 2020. The lower, broader tail is the comet’s dust tail, while the thinner, upper tail is the comet’s ion tail.

The dust tail is created by dust lifting off the surface of the comet’s nucleus, and it trails behind the comet in its orbit. The ion tail is made up of gases that have been ionized by stripped of electrons by the Sun’s intense light. These ionized gases are buffeted by the solar wind, the Sun’s constant outflow of magnetized material, forcing the ion tail to extend directly away from the Sun. The Sun is out of the image to the left.

Image Credits: NASA / JHUAPL / NRL / Parker Solar Probe / Guillermo Stenborg

A Wide Spectrum Look at M101

It’s one of the last entries in Charles Messier’s famous catalog, but M101 is definitely not one of the least. The galaxy is big—roughly 170,000 light-years across, almost twice the size of our own Milky Way Galaxy. This multiwavelength view is a composite of images recorded by space-based telescopes. Color coded from X-rays to infrared wavelengths (high to low energies), the image data was taken from the Chandra X-ray Observatory (x-rays, purple), the Galaxy Evolution Explorer (ultraviolet, blue), the Hubble Space Telescope (visible light, yellow), and the Spitzer Space Telescope (infrared, red). While the X-ray data shows the multimillion degree gas around M101’s exploded stars and neutron star and black hole binary star systems, the lower energy data shows the stars and dust that define M101’s grand spiral arms. Known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major. It’s about 25 million light-years away.

Image Credit: NASA


UGC 1382About 250 million light-years away in a neighborhood of our universe that astronomers had considered quiet and unremarkable, scientists have uncovered an enormous, bizarre galaxy possibly formed from the parts of other galaxies. In optical light (left), UGC 1382 appears to be a simple elliptical galaxy, but spiral arms appeared when astronomers incorporated ultraviolet and deep optical data (middle). Combining that with a view of low-density hydrogen gas (shown in green at right), revealeded that UGC 1382 is gigantic.

It turns out that UGC 1382, a galaxy that had originally been thought to be old, small and typical is 10 times bigger than previously thought and, unlike most galaxies, its insides are younger than its outsides, almost as if it had been built using spare parts. It’s a rotating disk of low-density gas where stars don’t form quickly because the gas is so spread out. UGC 1382 is about 718,000 light-years across, more than seven times wider than the Milky Way, making it one of the three largest isolated disk galaxies ever discovered.

Image Credit: NASA / SDSS / NRAO

Blowing a Bubble in Space

U Camelopardalis (aka U Cam) is a star nearing the end of its life. When stars run low on fuel for their normal fusion reactions, they become unstable. Every few thousand years, U Cam coughs out an almost spherical shell of gas as helium from its core begins to fuse. The gas ejected in the star’s latest eruption can be seen in this picture as a faint bubble around the star.

U Cam is an example of a carbon star. That’s a rare type of star with an atmosphere that contains more carbon than oxygen. Because of relatively low surface gravity, as much as half of the total mass of a carbon star may we swept away by powerful stellar winds. U Cam is located in the constellation of Camelopardalis (The Giraffe) which is near the North Celestial Pole, U Cam is much smaller than it appears in this image taken by the Hubble Space Telescope. The star would easily fit within a single pixel in the image. However, it is bright enough to saturate the camera’s photosensors which causes the star look much larger.

The shell of gas, both much larger and much fainter than its parent star, is visible in the picture. Gas clouds from expolsions are often quite irregular and unstable, but the shell of gas ejected from U Cam is almost perfectly spherical.

Image Credit: NASA

The History of the Universe, Part One

The Wilkinson Microwave Anisotropy Probe (WMAP) was a NASA Explorer mission that made fundamental measurements of cosmology—the study of the properties of our universe as a whole.

The structure of the universe evolved from the Big Bang, as represented by WMAP’s “baby picture” of the Cosmic Microwave Background (the afterglow of the Big Bang), through the clumping and ignition of matter, and continuing up to the present. This video condenses that almost 14 billion year history into 45 seconds.

Video Credit: NASA