Why don’t Green Comets Have Green Tails?

Comet C/2014 Q2 Lovejoy photographed overnight December 28-29, 2014 remotely from Siding Spring, Australia as passed within 1/6 degree of the globular cluster M79. The coma glows green from fluorescing carbon molecules while the narrow ion tail is carbon monoxide gas fluorescing in UV sunlight. Credit: Rolando Ligustri

Green is an unusual color in astronomy. It is the color to which our eyes are most sensitive, and yet few things in the night sky actually appear green. There are, for example, no green stars, only yellow-white, red, and blue ones. But there can be green comets, and we are still learning why.

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Astronomers Find the Biggest Structure in the Milky Way, a Filament of Hydrogen 1,600 Light-Years Long

Composite image of the Milky Way's core created by Hubble, Spitzer, and Chandra telescopes. Credit X-ray: NASA/CXC/UMass/D. Wang et al.; Optical: NASA/ESA/STScI/D.Wang et al.; IR: NASA/JPL-Caltech/SSC/S.Stolovy

Roughly 13.8 billion years ago, our Universe was born in a massive explosion that gave rise to the first subatomic particles and the laws of physics as we know them. About 370,000 years later, hydrogen had formed, the building block of stars, which fuse hydrogen and helium in their interiors to create all the heavier elements. While hydrogen remains the most pervasive element in the Universe, it can be difficult to detect individual clouds of hydrogen gas in the interstellar medium (ISM).

This makes it difficult to research the early phases of star formation, which would offer clues about the evolution of galaxies and the cosmos. An international team led by astronomers from the Max Planck Institute of Astronomy (MPIA) recently noticed a massive filament of atomic hydrogen gas in our galaxy. This structure, named “Maggie,” is located about 55,000 light-years away (on the other side of the Milky Way) and is one of the longest structures ever observed in our galaxy.

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JWST Deploys its Secondary Mirror. It’s a Real Telescope Now

Webb’s primary mirror intercepts red and infrared light traveling through space and reflects it onto a smaller secondary mirror. The secondary mirror then directs the light into the scientific instruments where it is recorded. Credits: IMAGE: STScI, Andi James (STScI)

Ladies and gentlemen, we have a telescope.

The secondary mirror on the James Webb Space Telescope was successfully deployed in space today, an incredibly important milestone.

“We are 600,000 miles from Earth and we have a telescope,” said Bill Ochs, JWST program manager, speaking triumphantly to his team after the secondary mirror was deployed and then latched in place.

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China’s Tianwen-1 Spacecraft Took a Selfie Using a Tiny, Secondary Spacecraft

A remote 'selfie' camera took this image of the Tainwen-1 spacecraft in orbit of Mars. Credit: CNSA.

Remember how China’s Tianwen-1 spacecraft released a remote camera to take a picture of itself during its flight to Mars, back in late 2020? Now in Mars orbit, Tianwen-1 has done it again, releasing another mini remote camera. Except this time, the planet Mars is part of the view.

The images are stunning.

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Astronomers Find 70 Planets Without Stars Floating Free in the Milky Way

This artist’s impression shows an example of a rogue planet with the Rho Ophiuchi cloud complex visible in the background. Rogue planets have masses comparable to those of the planets in our Solar System but do not orbit a star, instead roaming freely on their own. Image Credit: ESO/M. Kornmesser/S. Guisard

The field of extrasolar planet studies continues to reveal some truly amazing things about our Universe. After decades of having just a handful of exoplanets available for study, astronomers are now working with a total of 4,884 confirmed exoplanets and another 8,288 awaiting confirmation. This number is expected to increase exponentially in the coming years as next-generation missions like the James Webb Space Telescope (JWST), Euclid, PLATO, and the Nancy Grace Roman Space Telescope (RST) reveal tens of thousands more.

In addition to learning a great deal about the types of exoplanets that are out there and what kind of stars are known to give rise to them, astronomers have also made another startling discovery. There is no shortage of exoplanets in our galaxy that don’t have a parent star. Using telescopes from around the world, a team of astronomers recently discovered 70 additional free-floating planets (FFPs), the largest sample of “Rogue Planets” discovered to date, and nearly doubling the number of FFPs available for study.

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Success! Webb Sunshield Now Fully Deployed

Illustration of NASA's James Webb Space Telescope. Credits: NASA
Illustration of NASA's James Webb Space Telescope. Credits: NASA

If you felt a little more tension – and perhaps more goosebumps — in the Universe today, it’s probably because the James Webb Space Telescope’s sunshield is now completely and successfully deployed! All five layers of the sunshield have been fully extended and “tensioned” into the final taut, kite-shaped configuration. This is a huge accomplishment (and huge relief) for the entire international Webb mission

“This has been many years in the making, and is a really big moment for the entire team,” said the JWST mission operations manager after the final events to tension and latch the sunshield were confirmed. “There’s nothing cooler in space than JWST!”

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2029 Will be the Perfect Year to Launch a Mission to Sedna

Artist's conception of Sedna, the TNO that orbits in the outer edges of the Solar System. Credit: NASA/JPL-Caltech

Object 90377 Sedna – a distant trans-Neptunian object known best for its highly elliptical, 11,390-year long orbit – is currently on its way towards perihelion (its closest approach to the Sun) in 2076. After that, Sedna will swing out into deep space again and won’t be back for millennia, making this flyby a once-in-a-lifetime (or, once in ~113 lifetimes) opportunity to study an object from the far reaches of our solar system. There are no missions to Sedna in the works just yet, but astronomers are beginning to plan for the possibility, and the ideal launch date for such a mission is approaching fast, with two of the best launch windows coming up in 2029 and 2034.

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A Detailed Scan of the Milky Way Finds Possible “Fossil” Spiral Arms

Looking deep into the Universe, the NASA/ESA Hubble Space Telescope catches a passing glimpse of the numerous arm-like structures that sweep around this barred spiral galaxy, known as NGC 2608. Appearing as a slightly stretched, smaller version of our Milky Way, the peppered blue and red spiral arms are anchored together by the prominent horizontal central bar of the galaxy. In Hubble photos, bright Milky Way stars will sometimes appear as pinpoints of light with prominent lens flares. A star with these features is seen in the lower right corner of the image, and another can be spotted just above the pale centre of the galaxy. The majority of the fainter points around NGC 2608, however, lack these features, and upon closer inspection they are revealed to be thousands of distant galaxies. NGC 2608 is just one among an uncountable number of kindred structures. Similar expanses of galaxies can be observed in other Hubble images such as the Hubble Deep Field which recorded over 3000 galaxies in one field of view.

As we learn more about the cosmos, it’s interesting how some of the greatest discoveries continue to happen close to home. This is expected to continue well into the future, where observations of Cosmic Dawn and distant galaxies will take place alongside surveys of the outer Solar System and our galaxy. In this latter respect, the ESA’s Gaia observatory will continue to play a vital role. As an astrometry mission, Gaia has been to determine the proper position and radial velocity of over a billion stars to create a three-dimensional map of the Milky Way.

Using data from Gaia’s third early Data Release (eDR3) and Legacy Survey data – from the Sloan Digital Sky Survey (SDSS) – an international team of astronomers created a new map of the Milky Way’s outer disk. In the process, they discovered evidence of structures in this region that include the remnants of fossil spiral arms. This discovery will shed new light on the formation and history of the Milky Way and may lead to a breakthrough in our understanding of galactic evolution.

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JWST Just Deployed a Sail That Lets it Stop Getting Pushed Around by the Sun’s Radiation.

Screenshot from NASA TV showing the Webb telescope after release from the rocket stage. Credit: NASA.

On December 25th, 2021, astronomers and space exploration enthusiasts got the greatest Christmas present of all! After years of delays, cost overruns, and additional testing, the James Webb Space Telescope (JWST) launched from Europe’s Spaceport in Kourou, French Guiana. In what was a real nail-biter, the Ariane 5 rocket and its precious payload reached orbit without a hitch. But as is so often the case, the deployment of the JWST was just the first in a series of “hurry up and wait” episodes.

Typically, periods of waiting are seeing are accompanied by plenty of worry and doubt. Luckily, there have been several positive developments since the JWST launched that could help alleviate these anxieties. The latest is how the telescope successfully deployed its aft momentum flap, an instrument that will keep the telescope oriented during its mission. The news was announced yesterday (December 30th) via @NASAWebb, NASA’s official Twitter account for the Webb telescope, and the JWST page at NASA Blogs.

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An Exoplanet Found Protected by a Magnetosphere

Today’s astronomers are busy building the census of extrasolar planets, which has reached a total of 4,884 confirmed planets, with another 8,288 candidates awaiting confirmation. Now that the James Webb Space Telescope (JWST) has finally been launched, future surveys will be reaching beyond mere discovery and will be focused more on characterization. In essence, future exoplanet surveys will determine with greater certainty which planets are habitable and which are not.

One characteristic that they will be on the lookout for in particular is the presence of planetary magnetic fields (aka. magnetospheres). On Earth, the atmosphere and all life on the surface are protected by a magnetic field, which is why they are considered crucial to habitability. Using data from the venerated Hubble Space Telescope (HST), an international team of astronomers reported the detection of a magnetic field around an exoplanet for the first time!

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