The European Southern Observatory has begun imaging the Sun for the first time, using its Atacama Large Millimeter/submillimeter Array (ALMA)—a suite of large dish-type telescopes located on a plateau 16,000 feet above sea level in the arid Chilean Andes. ALMA’s capabilities to observe in millimeter and submillimeter wavelengths allow imaging of the Sun’s dynamic chromosphere and the features within it, such as the center of a sunspot (above) that’s easily twice the size of Earth.
Read more here from ESO: ALMA Starts Observing the Sun
Researchers using the High Accuracy Radial velocity Planet Searcher (HARPS) instrument on ESO’s 3.6-meter telescope at La Silla have detected “unexpected” changes in the brightness of Ceres during observations made in July and August of 2015. Variations in line with Ceres’ 9-hour rotational period were expected, but other fluctuations in brightness were also found that indicate albedo changes on a daily, diurnal basis.
Long story short: Ceres is slowly “blinking.”
I just had to share this beautiful image by ESO photo ambassador Babak Tafreshi; it shows a star-filled night sky above the Chajnantor Plateau on the border of Chile and Bolivia, the site of the Atacama Large Millimeter/submillimeter Array (ALMA) observatory. The site, chosen for its remote location and incredibly clear, dry sky, is one of the best on Earth for observing the most distant objects in the Universe.
The jagged snow features in the foreground are known as penitentes, for their resemblance to the conical hats of Spanish religious group members known as the Nazarenos. They are the result of Sun and wind erosion on high-altitude snow, although the exact process isn’t entirely known.
We all know that Saturn is encircled by a system of rings, and perhaps you also know about the fainter rings around Uranus, Jupiter, and Neptune. But today, ESO astronomers have revealed a surprising discovery: there are also rings surrounding the asteroid 10199 Chariklo, a small, distant world orbiting the Sun far beyond Saturn.
This makes 250-km-wide Chariklo the fifth world ever found to have rings, after the four planets mentioned previously, and, based on the observations, it could also even have its own moon.
“As well as the rings, it’s likely that Chariklo has at least one small moon still waiting to be discovered,” said Felipe Braga-Ribas of the Observatório Nacional/MCTI in Rio de Janeiro who planned the observation campaign and is lead author on the new paper.
What are asteroids made of? While composed of metals, rocks, ices, and also many elements that are difficult to find and retrieve here on Earth — hence the growing interest in asteroid-mining missions — these drifting denizens of the Solar System have many different possible ways of forming. Some may be dense hunks of rock and metal, created during violent collisions and breakups of once-larger bodies, while others may be little more than loose clusters of gravel held together by gravity. Knowing how to determine the makeup of an asteroid is important to astronomers, not only to know its history but also to be better able to predict its behavior as it moves through space, interacting with other bodies — other asteroids, future exploration craft, radiation from the Sun, and potentially (although we hope not!) our own planet Earth.
Now, using the European Southern Observatory’s New Technology Telescope (NTT) researchers have probed the internal structure of the 535-meter-long near-Earth asteroid Itokawa, and found out that different parts have greatly varying densities, possibly an indication of how it — and others like it — formed.
These days it seems exoplanets are being discovered nearly every week, with “super-Earths”, “hot Jupiters” and “cold Neptunes” being identified (or at least announced as solid candidates) within star systems all around our neck of the galaxy. To top it all off, today the European Southern Observatory announced that an Earth-mass world has now been found orbiting Alpha Centauri B — quite literally the “star next door.”