Space Stories: Jovian Moons, Charon’s Canyons, and a New Space Telescope

Posted on by onespaceman2000
Image (Credit): Jupiter as seen by the NASA/ESA Hubble Space Telescope. (NASA, ESA, A. Simon (Goddard Space Flight Center), and M.H. Wong (University of California, Berkeley)

Here are some recent stories of interest.

—Live Science: “Jupiter Officially has the Most Moons in the Solar System, Discovery of 12 New Satellites Confirms“

Jupiter was already the king of the solar system, and new discoveries give the massive planet another way to reign supreme: It now has the most moons. Twelve new moons discovered orbiting Jupiter have been confirmed, bumping the count from 80 to 92, and knocking Saturn — which has 83 moons — down a peg. 

—Phys.org: “Models Explain Canyons on Pluto’s Large Moon Charon“

In 2015, when NASA’s New Horizons spacecraft encountered the Pluto-Charon system, the Southwest Research Institute-led science team discovered interesting, geologically active objects instead of the inert icy orbs previously envisioned. An SwRI scientist has revisited the data to explore the source of cryovolcanic flows and an obvious belt of fractures on Pluto’s large moon Charon. These new models suggest that when the moon’s internal ocean froze, it may have formed the deep, elongated depressions along its girth but was less likely to lead to cryovolcanoes erupting with ice, water and other materials in its northern hemisphere.

—Big Think: “NASA’s Habitable Worlds Observatory to Finally Answer the Epic Question: “Are we Alone?”“

…perhaps the biggest question of all — that of “Are we alone in the Universe?” — remains a mystery. While the current generation of ground-based and space-based telescopes can take us far into the Universe, this is a question that’s currently beyond our reach. To get there, we’ll need to directly image Earth-like exoplanets: planets with sizes and temperatures similar to Earth, but that orbit Sun-like stars, not the more common red dwarf stars like Proxima Centauri or TRAPPIST-1. Those capabilities are precisely what NASA is aiming for with its newly announced flagship mission: the Habitable Worlds Observatory. It’s an ambitious project but one that’s well worth it. After all, finding out we’re not alone in the Universe would quite possibly be the biggest revolution in all of science history.

Pic of the Week: Stellar Glitter

Posted on by onespaceman2000
Image (Credit): NGC 2260 in the constellation Vela. (NASA, ESA, and T. von Hippel (Embry-Riddle Aeronautical University); Processing: Gladys Kober (NASA/Catholic University of America))

This week’s image containing all of the sparkling stellar glitter is from the Hubble Space Telescope. Hubble continues to astound with an ongoing stream of amazing images.

Here is a little more from NASA on the image above:

This glittering group of stars, shining through the darkness like sparks left behind by a firework, is NGC 2660 in the constellation Vela, best viewed in the southern sky. NGC 2660 is an open cluster, a type of star cluster that can contain anywhere from tens to a few hundreds of stars loosely bound together by gravity. The stars of open clusters form out of the same region of gas and dust and thus share many characteristics, such as age and chemical composition. Unlike globular clusters – their ancient, denser, and more tightly-packed cousins – open clusters are easier to study since astronomers can more easily distinguish between individual stars. Their stars can be old or young, and they may disperse after a few million years into the spiral or irregular galaxies where they are born.

The spikes surrounding many of the stars in this image are “diffraction spikes,” which occur when the glow from bright points of light reflects off of Hubble’s secondary mirror support. The bright red object to the left with the very prominent diffraction spikes is a foreground star that is not part of the cluster. Hubble observed this open cluster as part of a program to study the ages of white dwarf stars in open clusters.

Good Article: The Old and the New in Space Telescopes

Posted on by onespaceman2000
Image (Credit): Costs and timescales of past, current and future NASA missions. Cost is at launch, i.e. does not include servicing missions. Development timescale indicates time from survey recommendation to launch. For future missions, the estimated cost is a minimum, assuming immediate start and optimum budget profile. (PhysicsWorld using data taken from the NASA Astro2020 decadal survey)

The above table from a Physics World article, “‘Great observatories’ – the next generation of NASA’s space telescopes, and their impact on the next century of observational astronomy,” gives you some idea about what is already floating in space and what we hope to launch in the future.

Take a look at the article to learn more about the science and politics surrounding space telescopes and the likelihood we will see other great space telescopes like the James Webb Space Telescope in the near future.

Pic of the Week: Distant Stellar Nursery

Posted on by onespaceman2000
Image (Credit): CB 130-3 as captured by the Hubble Space Telescope. (ESA/Hubble, NASA & STScI, C. Britt, T. Huard, A. Pagan)

This week’s image comes from the Hubble Space Telescope. It shows a distant cloud of gas and dust known as CB 130-3. Such clouds can create new stars, as explained by the European Space Agency:

CB 130-3 is an object known as a dense core, a compact agglomeration of gas and dust. This particular dense core is in the constellation Serpens and seems to billow across a field of background stars.

Dense cores like CB 130-3 are the birthplaces of stars and are of particular interest to astronomers. During the collapse of these cores enough mass can accumulate in one place to reach the temperatures and densities required to ignite hydrogen fusion, marking the birth of a new star. While it may not be obvious from this image, a compact object teetering on the brink of becoming a star is embedded deep within CB 130-3.

Astronomers used Hubble’s Wide Field Camera 3 to better understand the environment surrounding this fledgling star. As this image shows, the density of CB 130-3 isn’t constant; the outer edges of the cloud consist of only tenuous wisps, whereas at its core CB 130-3 blots out background light entirely. The gas and dust making up CB 130-3 affect not only the brightness but also the apparent color of background stars, with stars toward the cloud’s center appearing redder than their counterparts at the outskirts of this image. Astronomers used Hubble to measure this reddening effect and chart out the density of CB 130-3, providing insights into the inner structure of this stellar nursery.

Pic of the Week: Hickson Compact Group 40

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Image (Credit): The NASA/ESA Hubble Space Telescope view of five galaxies, called the Hickson Compact Group 40. (NASA/ESA Hubble)

This week’s image is from the NASA/ESA Hubble Space Telescope. It shows an amazing collection of five galaxies in close proximity to one another in what is known as the Hickson Compact Group 40. In about one billion years they are expected to coalesce into one large galaxy.

Here is the summary from the Hubble site:

This menagerie includes three spiral-shaped galaxies, an elliptical galaxy and a lenticular (lens-like) galaxy. Somehow, these different galaxies have crossed paths to create an exceptionally crowded and eclectic galaxy sampler.

Caught in a leisurely gravitational dance, the whole group is so crowded that it could fit within a region of space that is less than twice the diameter of our Milky Way’s stellar disc.

Though such galaxy groupings can be found in the heart of huge galaxy clusters, these galaxies are notably isolated in their own small patch of the Universe, in the direction of the constellation Hydra.

One possibility is that there’s a lot of dark matter (a poorly understood and invisible form of matter) associated with these galaxies. If they come close together the dark matter can form a big cloud within which the galaxies orbit. As the galaxies plough through the dark matter they feel a frictional force that results from its gravitational effects. This slows their motion and makes the galaxies lose energy, so they fall together. Therefore, this snapshot catches the galaxies at a very special moment in their lifetimes. In about 1 billion years they will eventually collide and merge to form a single giant elliptical galaxy.

Astronomers have studied this compact galaxy group not only in visible light, but in radio, infrared, and at X-ray wavelengths. Almost every one of the galaxies has a compact radio source at its core, which could be evidence for the presence of a supermassive black hole. X-ray observations show that the galaxies have been gravitationally interacting as witnessed by the presence of a lot of hot gas amongst them. Infrared observations reveal clues to the rate of formation of new stars.

Though over 100 such compact galaxy groups have been catalogued in sky surveys going back several decades, Hickson Compact Group 40 is one of the most densely packed. Observations suggest that such tight groups may have been more abundant in the early Universe and provided fuel for powering black holes, known as quasars, whose light from superheated inflating material blazed across space. Studying the details of galaxies in nearby groups like this helps astronomers sort out when and where galaxies assembled themselves, and what they are assembled from.