Astronomy Archives

October 3, 2019October 4, 2019 by Matt Williams

Earth, Solar System, Milky Way. Are they Getting More or Less Massive Over Time?

Artist's impression of the Milky Way Galaxy. Credit: ESO

According to the most widely-accepted cosmological models, the first galaxies began to form between 13 and 14 billion years ago. Over the course of the next billion years, the cosmic structures we’ve all come to know emerged. These include things like galaxy clusters, superclusters, and filaments, but also galactic features like globular clusters, galactic bulges, and Supermassive Black Holes (SMBHs).

However, like living organisms, galaxies have continued to evolve ever since. In fact, over the course of their lifetimes, galaxies accrete and eject mass all the time. In a recent study, an international team of astronomers calculated the rate of inflow and outflow of material for the Milky Way. Then the good folks at astrobites gave it a good breakdown and showed just how relevant it is to our understanding of galactic formation and evolution.

October 2, 2019October 4, 2019 by Matt Williams

Exoplanet Orbits its Star Every 18 Hours. The Quickest Hot-Jupiter Ever Found

Using data obtained by Kepler and numerous observatories around the world, an international team has found a Super-Earth that orbits its orange dwarf star in just 14 hours. Credit: M. Weiss/CfA

In the past decade, thousands of planets have been discovered beyond our Solar System. These planets have provided astronomers with the opportunity to study planetary systems that have defied our preconcieved notions. This includes particularly massive gas giants that are many times the size of Jupiter (aka. “super-Jupiters”). And then there are those that orbit particularly close to their suns, otherwise known as “hot-Jupiters”.

Conventional wisdom indicates that gas giants should exist far from their suns and have long orbital periods that can last for a decade or longer. However, in a recent study, an international team of astronomers announced the detection of a “hot-Jupiter” with the shortest orbital period to date. Located 1,060 light-years away from Earth, this planet (NGTS-10b) takes just 18 hours to complete a full orbit of its sun.

October 1, 2019October 1, 2019 by Evan Gough

A Red Dwarf Star Has a Jupiter-Like Planet. So Massive it Shouldn’t Exist, and Yet, There It Is

Artist's illustration of the newfound gas-giant planet GJ 3512b, which circles a red dwarf star. (Image credit: Guillem Anglada-Escude—IEEC/Science-wave, using SpaceEngine.org (CC BY 4.0))

Thanks to the Kepler mission and other efforts to find exoplanets, we’ve learned a lot about the exoplanet population. We know that we’re likely to find super-Earths and Neptune-mass exoplanets orbiting low-mass stars, while larger planets are found around more massive stars. This lines up well with the core accretion theory of planetary formation.

But not all of our observations comply with that theory. The discovery of a Jupiter-like planet orbiting a small red dwarf means our understanding of planetary formation might not be as clear as we thought. A second theory of planetary formation, called the disk instability theory, might explain this surprising discovery.

September 30, 2019September 30, 2019 by David Dickinson

Tracking Twilight: ‘Purple Sunset Effect’ Seen Worldwide

Has twilight looked at little… purple to you as of late? The ‘purple sunset’ effect is subtle, but currently noticeable on a clear evening. Sunsets are always colorful events, as the Sun’s rays shine through a thicker layer of the atmosphere at an oblique angle, scattering out at longer, redder wavelengths. When the air is clear and relatively dust free, this effect is at a minimum… but when the upper atmosphere becomes saturated with dust particles and aerosols, the sky can erupt in a panoply of colors at twilight.

September 29, 2019September 29, 2019 by Matt Williams

Musk Presents the Orbital Starship Prototype. Flights will Begin in Six Months

Artist's illustration of a SpaceX Starship lands on Mars. Credit: SpaceX

On Saturday, Sept. 28th, SpaceX founder Elon Musk presided over a media circus at their testing facility in Boca, Chica, Texas. With the fully-assembled Starship Mk.1 as his backdrop, Musk shared the latest updates on the Starship launch system, which include a timetable for when the first test-flights, commercial flights and crewed flights will commence. Sometime next year, he promised, it will begin taking passengers to space!

September 28, 2019September 28, 2019 by Matt Williams

New Technique for Estimating the Mass of a Black Hole

A Hubble Space Telescope view of M87's core and its jet. it points nearly directly at us and is also known as a blazar. Astronomers are studying other blazars that have meandering jets and think that binary black holes may be hidden inside some of them. Courtesy STScI.

Black holes are the one the most intriguing and awe-inspiring forces of nature. They are also one of the most mysterious because of the way the rules of conventional physics break down in their presence. Despite decades of research and observations there is still much we don’t know about them. In fact, until recently, astronomers had never seen an image of black hole and were unable to guage their mass.

However, a team of physicist from the Moscow Institute of Physics and Technology (MIPT) recently announced that they had devised a way to indirectly measure the mass of a black hole while also confirming its existence. In a recent study, they showed how they tested this method on the recently-imaged supermassive black hole at the center of the Messier 87 active galaxy.

September 27, 2019September 27, 2019 by Evan Gough

Astronomers Have Found a Place With Three Supermassive Black Holes Orbiting Around Each Other

The three black holes at the center of three separate galaxies as imaged by Chandra and other telescopes. Image Credit: Credit: X-ray: NASA/CXC/George Mason Univ./R. Pfeifle et al.; Optical: SDSS & NASA/STScI

Astronomers have spotted three supermassive black holes (SMBHs) at the center of three colliding galaxies a billion light years away from Earth. That alone is unusual, but the three black holes are also glowing in x-ray emissions. This is evidence that all three are also active galactic nuclei (AGN,) gobbling up material and flaring brightly.

This discovery may shed some light on the “final parsec problem,” a long-standing issue in astrophysics and black hole mergers.

September 26, 2019September 26, 2019 by Matt Williams

WFIRST Gets its Coronagraph, to Block the Light of Stars and Reveal Their Planets

NASA's Wide Field Infrared Survey Telescope (WFIRST) will capture Hubble-quality images covering swaths of sky 100 times larger than Hubble does, enabling cosmic evolution studies. Its Coronagraph Instrument will directly image exoplanets and study their atmospheres. Credits: NASA/GSFC/Conceptual Image Lab — NASA's Wide Field Infrared Survey Telescope (WFIRST) will capture Hubble-quality images covering swaths of sky 100 times larger than Hubble does. These enormous images will allow astronomers to study the evolution of the cosmos. Its Coronagraph Instrument will directly image exoplanets and study their atmospheres. Credits: NASA/GSFC/Conceptual Image Lab

In the next decade, NASA will be sending some truly impressive facilities to space. These include the next-generation space telescopes like the James Webb Space Telescope (JWST) and the Wide-Field Infrared Space Telescope (WFIRST). Building on the foundation established by Hubble, WFIRST will use its advanced suite of instruments to investigate some of the deepest mysteries of the Universe.

One of these instruments is the coronagraph that will allow the telescope to get a clear look at extra-solar planets. This instrument recently completed a preliminary design review conducted by NASA, a major milestone in its development. This means that the instrument has met all design, schedule and budget requirements, and can now proceed to the next phase in development.

September 25, 2019September 25, 2019 by Evan Gough

This Summer’s Asteroid Near-Miss Helped Greenlight NASA’s NEOCam Mission to Search the Skies for Killer Spacerocks

An artist's conception of an NEO asteroid orbiting the Sun. Credit: NASA/JPL.

Last July, a once-in-a-lifetime event happened. Not the good kind; the football-field-sized-asteroid near-miss kind. And that near miss is the catalyst for a renewed effort from NASA to detect more dangerous space-rocks that might threaten Earth.

Last summer’s near-miss asteroid was named 2019 OK, and it passed within about 77,000 km (48,000 miles) of Earth. It managed to slip past all of our detection methods and came within 0.19 lunar distances to Earth. In astronomical terms, that is remarkably close.

We only had 24 hours notice that the asteroid was coming, thanks to a small telescope in Brazil that spotted it. That near miss has sparked a renewed conversation on planetary defense and on NASA’s role in it.

It also left people wondering how this could happen.

September 24, 2019September 24, 2019 by Matt Williams

Lockheed Wins the Contract to Build Six More Orion Capsules

Orion is NASA’s deep space exploration spaceship that will carry astronauts from Earth to the Moon and bring them safely home. Credit: Lockheed Martin

When NASA sends astronauts back to the Moon and to Mars, the Orion Multipurpose Crew Vehicle (MPCV) will be what takes them there. To build these next-generation spacecraft, NASA contracted aerospace manufacturer Lockheed Martin. Combined with the massive Space Launch System (SLS), the Orion spacecraft will allow for long-duration missions beyond Low Earth Orbit (LEO) for the first time in over 50 years.

On Monday, Sept. 23rd, NASA and Lockheed Martin announced that they had finalized a contract for the production and operations of six missions using the Orion spacecraft, with the possibility of up to twelve being manufactured in total. This fulfills the requirements for NASA’s Project Artemis and opens the possibility for further missions to destinations like Mars and other locations in deep-space.