Callisto is the one of the Galilean moons of Jupiter, the second largest. Its surface is old, showing the highest coverage by impact craters of any large body in the Solar System, but it has no volcanoes or large mountains. Callisto’s surface is one large ice-field, littered with cracksand craters from billions of years of collisions. This picture was taken in 2001 by the Galileo spacecraft.

Image Credit: NASA

An Isolated Galaxy

The loneliest of galaxiesMCG+01-02-015’s unsentimental naming befits its position within the cosmos: it is a void galaxy, located in an almost empty gap between local groups of galaxies. If our galaxy, the Milky Way, were as isolated, we would not even have known of the existence of other galaxies until the development of strong telescopes and detectors in the 1960s. (Instead, some of our neighboring galaxies such as Andromeda and the Magellanic Clouds can be seen by the naked eye.)

BTW, those three bright stars with the cross-shaped diffraction spikes are in the foreground. They’re near by in the Milky Way.

Image Credit: NASA


This Voyager 2 color image of the Uranian satellite, Miranda is a composite of three shots taken through green, violet, and ultraviolet filters from the narrow angle camera. It is the best color image of Miranda returned to date. Miranda, just 480 km across, is the smallest of Uranus’ five major satellites. It was taken in 1986 during Voyager 2’s fly of Uranus.

Image Credit: NASA

Early Images From Landsat 9

Landsat 9 is a joint mission of NASA and the U. S. Geological Survey. It was launched on 27 September, and has been going through its initial set of on-orbit testing. NASA has released some of the first pictures taken by the satellite’s two imaging systems. They are the Operational Land Imager 2 (OLI-2), which detects visible, near-infrared and shortwave-infrared light in nine wavelengths, and the Thermal Infrared Sensor 2 (TIRS-2), which detects thermal radiation in two wavelengths to measure Earth’s surface temperatures and its changes.

Data from both systems are shown above. The TIRS-2 images are on the right.

I was part of the design team for TIRS-2. My principal contribution was the design and testing of the power supples for the Main Electronics Box and the Focal Plane Electronics (the IR imaging detectors). I started working on TIRS-2 in February, 2016, and my part of the team delivered our hardware at the end of 2018. It’s nice to see data coming back to Earth.

Image Credit: NASA

Zooming in on CW Leonis

CW Leonis is a carbon star, a luminous red giant, whose atmosphere contains more carbon than oxygen. It’s believed to be in a late stage of its life, blowing off its own sooty atmosphere to eventually form a white dwarf.

Video Credit: ESA / Hubble, NASA, Dark Energy Survey / DOE / FNAL / NOIRLab / NSF / AURA, Digitized Sky Survey 2, E. Slawik, N. Risinger, M. Zamani
Music: tonelabs – Happy Hubble (
Creative Commons Attribution license (reuse allowed)

A Spaced-Out Brain

exposed_craniumThe brain-like blob called PMR 1 has been nicknamed the “Exposed Cranium.” This planetary nebula, located roughly 5,000 light-years away in the Vela constellation, is host to a hot, massive dying star that is rapidly losing its mass. The nebula’s interior, mushy and red in this view, is made up primarily of ionized gas, while its cooler outer consists of glowing hydrogen molecules.

In this infrared image taken by the Spitzer Space Telescope light at wavelengths of 3.6 µm is rendered in blue, 4.5 µm in green, and 8.0 µm in red.

Image Credit: NASA

A Class-X Solar Flare

The Solar Dynamics Observatory captured this image of a solar flare, the bright flash at the Sun’s lower center, at 1535 UTC (11:35 am ET) yesterday. This image was taken in extreme ultraviolet light that highlights the extremely hot material in flares, shown here in teal.

According to the NOAA Space Weather website, the flare caused a significant glitch in shortwave radio communications here on Earth

Image Credit: NASA

Two Clusters and White Dwarfs

Astronomers compare the cooling stars in two massive globular clusters, M13 and M3, to study the evolution of white dwarfs. These two clusters are about the same age and have roughly the same percentage of elements heavier than helium, but their populations of the kind of stars which will end their lives as white dwarfs are different. Thus, M13 and M3 form a natural laboratory the lives pf white dwarfs.

Image Credit: NASA / ESA

Smog on Saturn

north-poleThese two natural color images taken by the Cassini spacecraft show how Saturn’s north polar region has changed between 2012 and 2016. The color change is thought to be an effect of Saturn’s seasons. It’s believed that the change from a bluish color to a more golden hue is caused by the increased production of smog in the atmosphere as the north pole approached the summer solstice due in May, 2017.

The hexagon, Saturn’s six-sided jetstream, seems to act as a barrier preventing haze particles produced outside it from entering. If that’s the case, the polar atmosphere becomes clear of aerosols produced by photochemical reactions, reactions caused by sunlight, during the winter darkness. After Saturn’s northern spring equinox, the north pole polar is in continuous sunshine, and smog aerosols can be produced inside the hexagon, making the polar atmosphere appear hazy.

Image Credit: NASA