Universe Today

January 1, 2022January 1, 2022 by Matt Williams

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.

December 31, 2021December 31, 2021 by Matt Williams

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.

December 31, 2021December 31, 2021 by Matt Williams

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!

December 30, 2021December 30, 2021 by Nancy Atkinson

Still Nervous about JWST? Friday and Saturday’s Sunshield Deployments will be Nail-biters

The sunshield test unit on NASA's James Webb Space Telescope is unfurled for the first time. Credit: NASA

Every part of the James Webb Space Telescope’s (JWST’s) deployment is nerve-wracking, but some of the most nail-biting moments will happen on New Year’s Eve and New Year’s Day.

December 30, 2021December 30, 2021 by Nancy Atkinson

Want Updates on JWST? NASA’s Site Will Bury you in Data: Distance, Temperatures, Deployment Stats… Everything

Want to know the latest details on the James Webb Space Telescope? NASA has a “dashboard” where you can see all the data: location, the current deployment info, temperatures and more.

December 29, 2021December 29, 2021 by Nancy Atkinson

JWST’s Precise Launch and Near-Perfect Course Corrections Mean Fuel Savings. And That Means a Longer Mission

After a detailed analysis of where the James Webb Space Telescope is now (Dec. 29, 2021) and how it got there, NASA determined the observatory should have enough propellant to operate in space for significantly more than 10 years in space.

Webb’s mission lifetime was designed to be at least 5-1/2 years, and mission engineers and scientists were hoping for closer to 10 years.

December 29, 2021December 29, 2021 by Brian Koberlein

If you had Radio Telescopes for Eyes, one of the Biggest Things in the sky Would be a jet of Material Blasting out of a Nearby Galaxy

Merging X-ray data (blue) from NASA’s Chandra X-ray Observatory with microwave (orange) and visible images reveals the jets and radio-emitting lobes emanating from Centaurus A's central black hole. Credit: ESO/WFI (visible); MPIfR/ESO/APEX/A.Weiss et al. (microwave); NASA/CXC/CfA/R.Kraft et al. (X-ray)

One concept that’s difficult to visualize is the apparent size of objects in the sky. No the actual size of an object, but rather the amount of area an object covers in the sky. Apparent size depends on an object’s actual size and its distance from us. For example, the Sun is about 400 times wider than the Moon, but also about 400 times more distant, so the Sun and Moon have roughly the same apparent size.

December 29, 2021December 14, 2022 by David Dickinson

Astronomy 2022: Top Skywatching Events for the Coming Year

Meteor showers, eclipses and a fine opposition of Mars top out astronomy 2022.

2022 offers another fine sky watching year. 2021 brought us a remote Antarctic total solar eclipse, a surprise Christmas comet C/2021 A1 Leonard, and a return of solar activity with solar cycle Number 25. 2022 promises more of the same, as the solar cycle heads towards an active maximum in 2025. But there’s lots more in store in the sky in 2022. Alas, no ‘red nova’ is expected in 2022.

December 28, 2021December 28, 2021 by Matt Williams

New Calculations Show That an Interstellar Bussard Ramjet Drive Would Need a Magnetic Field Stretching 150 Million Kilometres

An artist's impression of a ramjet drive. Credit: NASA

In the 1960s, American physicist Robert W. Bussard proposed a radical idea for interstellar travel: a spacecraft that relied on powerful magnetic fields to harvest hydrogen directly from the interstellar medium. The high speed of this “ramjet” forces the hydrogen into a progressively constricted magnetic field until fusion occurs. The magnetic field then directs the resulting energy towards the rear of the spacecraft to generate propulsion.

As it’s come to be known, the Bussard Ramjet has since been popularized by hard science fiction writers like Poul Anderson, Larry Niven, Vernor Vinge, and science communicators like Carl Sagan. Unfortunately, a team of physicists recently analyzed the concept in more detail and concluded that Bussard’s idea is not practical. At a time when interstellar travel looks destined to become a real possibility, this analysis might seem like a wet blanket but is more of a reality check.

December 28, 2021December 28, 2021 by Nancy Atkinson

Here’s DART’s First Picture From Space. We Are Already Looking Forward to its Last Image

On Dec. 7, after opening the circular door to its telescopic imager, NASA’s DART captured this image of about a dozen stars near where the constellations Perseus, Aries and Taurus intersect. Credits: NASA/Johns Hopkins APL

It might not look like much, but here is the first monumental image from the Double Asteroid Redirection Test (DART). Earlier this month, a circular door covering the aperture of its DRACO telescopic camera was opened, allowing the camera to take its first image.

Now, imagine what the camera’s last image will be like: a REALLY closeup view of a binary asteroid system, Didymos and especially, its moonlet Dimorphos. The goal of DART is to intentionally collide with Dimorphos. If everything goes according to plan, this will alter the asteroid’s motion so that ground-based telescopes can accurately measure any changes.