interstellar medium Archives

April 14, 2023April 14, 2023 by Matt Williams

Twinkling Stars Supply the Dust That Leads to Life

Artist’s impression of the star in its multi-million year long and previously unobservable phase as a large, red supergiant. Credit: CAASTRO / Mats Björklund (Magipics)

When low to medium-mass stars exhaust their supply of hydrogen, they exit their main sequence phase and expand to become red giants – what is known as the Asymptotic Giant Branch (AGB) phase. Stars in this phase of their evolution become variable (experiences changes in brightness) to shed their outer lays, spreading dust throughout the interstellar medium (ISM) that is crucial to the development of planetary nebulas and protoplanetary systems. For decades, astronomers have sought to better understand the role Red Giant stars play.

Studying interstellar and protoplanetary dust is difficult because it is so faint in visible light. Luckily, this dust absorbs light and radiates brightly in the infrared (IR), making it visible to IR telescopes. Using archival data from now-retired Akari and Wide-field Infrared Survey Explorer (WISE) missions, a team of Japanese astronomers conducted the first long-period survey of dusty AGBs and observed that the variable intensity of these stars coincides with the amount of dust they produce. Since this dust plays an important role in the formation of planets, this study could shed light on the origins of life.

January 12, 2023January 12, 2023 by Matt Williams

Astronomers use the World's Biggest Radio Telescope to map new Features of the Milky Way

Artist impression of a fast radio burst. Credit: Danielle Futselaar

Despite everything astronomers have learned about the nature and structure of galaxies, there are still mysteries about the Milky Way. The reason for this is simple: since we are embedded in the Milky Way’s disk, we have difficulty mapping it and observing it as a whole. It’s also very challenging to observe the center of the galaxy, what lies beyond it, and features in the disk itself because of all the gas and dust between stars- the Interstellar Medium (ISM). However, by observing the Milky Way in the non-visible spectrum (radio, x-ray, gamma-ray, etc.), astronomers can see more of what’s out there.

There’s also the spectral line that corresponds to the emission frequency (1420 MHz) of cold neutral hydrogen gas (HI), which makes up the majority of the ISM. Using the Five-hundred-meter Aperture Spherical Telescope (FAST) – the most powerful radio telescope in the world near Guizhou, China – a team of scientists located more than 500 new faint pulsars. During the survey, the team simultaneously recorded the spectral line data with high spectral and spatial resolution, making it an extremely valuable resource for studying the structure of the Milky Way Galaxy and the life cycle of its stars.

February 16, 2022February 16, 2022 by Evan Gough

One of Life’s Building Blocks can Form in Space

A new kind of chemical reaction can explain how peptides can form on the icy layers of cosmic dust grains. Those peptides could have been transported to the early Earth by meteorites, asteroids or comets. Image Credit: © S. Krasnokutski / MPIA Graphics Department

Peptides are one of the smallest biomolecules and are one of life’s critical building blocks. New research shows that they could form on the surfaces of icy grains in space. This discovery lends credence to the idea that meteoroids, asteroids, or comets could have given life on Earth a kick start by crashing into the planet and delivering biological building blocks.

January 14, 2022January 14, 2022 by Evan Gough

Nearby Supernovae Exploded Just a few Million Years Ago, Leading to a Wave of Star Formation Around the Sun

Artist's illustration of the Local Bubble with star formation occurring on the bubble's surface. Scientists have now shown how a chain of events beginning 14 million years ago with a set of powerful supernovae led to the creation of the vast bubble, responsible for the formation of all young stars within 500 light years of the Sun and Earth. Credit: Leah Hustak (STScI)

The Sun isn’t the only star in this galactic neighbourhood. Other stars also call this neighbourhood home. But what’s the neighbourhood’s history? What triggered the birth of all those stars?

A team of astronomers say they’ve pieced the history together and identified the trigger: a series of supernovae explosions that began about 14 million years ago.

April 28, 2021April 28, 2021 by Andy Tomaswick

NASA is now Planning a Mission to go 1,000 AU From the Sun, Deep Into Interstellar Space

A different perspective can do wonders. Perceiving things from a different angle can both metaphorically and literally allow people to see things differently. And in space, there are an almost infinite number of angles that objects can be observed from. Like all perspectives, some are more informative than others. Sometimes those informative perspectives are also the hardest to reach.

Voyager’s two probes did an excellent job in allowing humanity to access some difficult new perspectives simply given their distance from the Earth. But now a team of over 500 scientists and volunteers is urging NASA to go even further to find a better perspective by sending a satellite to a distance 1000 times the distance from the Sun to the Earth – almost 10 times how far the Voyagers have traveled in over 35 years.

January 19, 2021January 19, 2021 by Evan Gough

This is a Simulation of the Interstellar Medium Flowing Like Smoke Throughout the Milky Way

The figure shows a section through the cube of the turbulence simulation. The colors show the density contrast relative to the mean density of the gas. Its turbulent structure is clearly recognizable. Image Credit: Federrath et al, 2021.

How do stars form?

We know they form from massive structures called molecular clouds, which themselves form from the Interstellar Medium (ISM). But how and why do certain types of stars form? Why, in some situations, does a star like our Sun form, versus a red dwarf or a blue giant?

That’s one of the central questions in astronomy. It’s also a very complex one.

June 4, 2020June 4, 2020 by Evan Gough

Astronomers Find the Source of the Huge Bubbles of Gas Flowing Out of the Milky Way, Still No Idea What Caused Them

Astronomers used the WHAM telescope to measure huge outflows of gas extending from the Milky Way’s center known as the Fermi Bubbles. They were able to measure the velocity, density and pressure of the gas for the first time, confirming and extending previous measurements made by using a distant quasar as a light source to look through and measure the gas. IMAGE BY DHANESH KRISHNARAO AND NASA

There’s an unusual paradox hampering research into parts of the Milky Way. Dense gas blocks observations of the galactic core, and it can be difficult to observe in visible light from our vantage point. But distant galaxies don’t always present the same obstacles. So in some ways, we can observe distant galaxies better than we can observe our own.

In order to gain a better understanding of the Galactic Center (GC) and the Interstellar Medium (ISM), a team of astronomers used a telescope called the Wisconsin H-Alpha Mapper (WHAM) to look into the core of the Milky Way in part of the optical light spectrum.

November 6, 2019February 12, 2020 by Evan Gough

What Voyager 2 Learned After Spending a Year in Interstellar Space

An artist concept depicting one of NASA's twin Voyager spacecraft, humanity's farthest and longest-lived spacecraft. Voyager 2 just lost contact with Earth while Voyager 1 is still reporting back. Credit: NASA/JPL-Caltech

Only two of humanity’s spacecraft have left the Solar System: NASA’s Voyager 1 and Voyager 2. Voyager 1 left the heliosphere behind in 2012, while Voyager 2 did the same on Nov. 5th, 2018. Now Voyager 2 has been in interstellar space for one year, and five new papers are presenting the scientific results from that one year.

June 26, 2019June 26, 2019 by Evan Gough

Hubble Finds Buckyballs in Space

For the first time, NASA's Spitzer Space Telescope has detected little spheres of carbon, called buckyballs, in a galaxy beyond our Milky Way galaxy. The space balls were detected in a dying star, called a planetary nebula, within the nearby galaxy, the Small Magellanic Cloud. What's more, huge quantities were found -- the equivalent in mass to 15 of our moons. An infrared photo of the Small Magellanic Cloud taken by Spitzer is shown here in this artist's illustration, with two callouts. The middle callout shows a magnified view of an example of a planetary nebula, and the right callout shows an even further magnified depiction of buckyballs, which consist of 60 carbon atoms arranged like soccer balls. In July 2010, astronomers reported using Spitzer to find the first confirmed proof of buckyballs. Since then, Spitzer has detected the molecules again in our own galaxy -- as well as in the Small Magellanic Cloud. Image Credit: NASA/JPL-Caltech

Scientists working with the Hubble Space Telescope have found a very complex molecule out there in space. Called Buckyballs, after renowned thinker Buckminster Fuller, they are a molecular arrangement of 60 carbon atoms (C60) in the rough shape of a soccer ball. Though it’s not the first time these exotic molecules have been spotted in space, it is the first time that Buckyball ions have been found.

April 11, 2019April 12, 2019 by Matt Williams

Voyager and Pioneer’s Grand Tour of the Milky Way

An artist's concept of Voyager 1's view of the Solar System. Voyager 1 is one of our first interstellar probes, though it's an inadvertent one. It has no particular destination. Credit: NASA, ESA, and J. Zachary and S. Redfield (Wesleyan University); Artist's Illustration Credit: NASA, ESA, and G. Bacon (STScI).

During the early 1990s, NASA’s Pioneer 10 and 11 probes became the first robotic missions to venture beyond Neptune. In 2012 and 2018, the Voyager 1 and 2 missions went even farther by crossing the heliopause and entering interstellar space. Eventually, these probes may reach another star system, where their special cargo (the Pioneer Plaques and the Golden Records) could find their way into the hands of another species.

Which raises an important question: where might these spacecraft eventually wander? To address this, Coryn Bailer-Jones of the Max Planck Institute for Astronomy and Davide Farnocchia of NASA’s Jet Propulsion Laboratory recently conducted a study that examined which star systems the Voyager and Pioneer probes will likely encounter as they drift through the Milky Way over the next few million years…