Astronomy Archives

April 15, 2019April 15, 2019 by Matt Williams

The Closest Star to the Sun, Proxima Centauri, has a Planet in the Habitable Zone. Life Could be There Right Now

Artist’s impression of Proxima b, which was discovered using the Radial Velocity method. Credit: ESO/M. Kornmesser

In August of 2016, astronomers from the European Southern Observatory (ESO) announced the discovery of an exoplanet in the neighboring system of Proxima Centauri. The news was greeted with consider excitement, as this was the closest rocky planet to our Solar System that also orbited within its star’s habitable zone. Since then, multiple studies have been conducted to determine if this planet could actually support life.

Unfortunately, most of the research so far has indicated that the likelihood of habitability are not good. Between Proxima Centauri’s variability and the planet being tidally-locked with its star, life would have a hard time surviving there. However, using lifeforms from early Earth as an example, a new study conducted by researchers from the Carl Sagan Institute (CSI) has shows how life could have a fighting chance on Proxima b after all.

April 10, 2019April 10, 2019 by Evan Gough

It’s Finally here. The First Ever Image of a Black Hole

The Event Horizon Telescope (EHT) — a planet-scale array of eight ground-based radio telescopes forged through international collaboration — was designed to capture images of a black hole. In coordinated press conferences across the globe, EHT researchers revealed that they succeeded, unveiling the first direct visual evidence of the supermassive black hole in the centre of Messier 87 and its shadow. The shadow of a black hole seen here is the closest we can come to an image of the black hole itself, a completely dark object from which light cannot escape. The black hole’s boundary — the event horizon from which the EHT takes its name — is around 2.5 times smaller than the shadow it casts and measures just under 40 billion km across. While this may sound large, this ring is only about 40 microarcseconds across — equivalent to measuring the length of a credit card on the surface of the Moon. Although the telescopes making up the EHT are not physically connected, they are able to synchronize their recorded data with atomic clocks — hydrogen masers — which precisely time their observations. These observations were collected at a wavelength of 1.3 mm during a 2017 global campaign. Each telescope of the EHT produced enormous amounts of data – roughly 350 terabytes per day – which was stored on high-performance helium-filled hard drives. These data were flown to highly specialised supercomputers — known as correlators — at the Max Planck Institute for Radio Astronomy and MIT Haystack Observatory to be combined. They were then painstakingly converted into an image using novel computational tools developed by the collaboration. Credit: Event Horizon Telescope Collaboration

“We have taken the first picture of a black hole.”

EHT project director Sheperd S. Doeleman of the Center for Astrophysics | Harvard & Smithsonian.

What was once un-seeable can now be seen. Black holes, those difficult-to-understand singularities that may reside at the center of every galaxy, are becoming seeable. The Event Horizon Telescope (EHT) has revealed the first-ever image of a black hole, and with this image, and all the science behind it, they may help crack open one of the biggest mysteries in the Universe.

April 10, 2019April 10, 2019 by David Dickinson

SOFIA Follows the Sulfur for Clues on Stellar Evolution

The high-flying SOFIA telescope is shedding light on where some of the basic building blocks for life may have originated from. A recent study published on The Astrophysical Journal: Letters led by astronomers from the University of Hawaii, including collaborators from the University of California Davis, Johns-Hopkins University, the North Carolina Museum of Natural Sciences, Appalachian State University, and several international partners (including funding from NASA), looked at a lingering mystery in planet formation: the chemical pathway of the element sulfur, and its implications and role in the formation of planets and life.

April 8, 2019December 2, 2019 by Tammy Plotner

Messier 83 – the Southern Pinwheel Galaxy

The beautiful spiral galaxy Messier 83 is located in the southern constellation Hydra. Credit: ESO

Welcome back to Messier Monday! Today, we continue in our tribute to our dear friend, Tammy Plotner, by looking at the Southern Pinwheel Galaxy – also known as Messier 83!

During the 18th century, famed French astronomer Charles Messier noticed the presence of several “nebulous objects” while surveying the night sky. Originally mistaking these objects for comets, he began to catalog them so that others would not make the same mistake. Today, the resulting list (known as the Messier Catalog) includes over 100 objects and is one of the most influential catalogs of Deep Space Objects.

One of these objects is the Southern Pinwheel Galaxy (aka. Messier 83), a barred spiral galaxy located 15.21 million light years from Earth in the southern constellation Hydra. With a spatial diameter of about 55,000 light years, or roughly half the size of the Milky Way, M83 is one of the nearest and brightest barred spirals in the sky.

Continue reading “Messier 83 – the Southern Pinwheel Galaxy”

April 6, 2019April 6, 2019 by Matt Williams

Now We Know That Dark Matter Isn’t Primordial Black Holes

The early universe. Credit: Tom Abel & Ralf Kaehler (KIPACSLAC)/ AMNH/NASA

For over fifty years, scientists have theorized that roughly 85% of matter in the Universe’s is made up of a mysterious, invisible mass. Since then, multiple observation campaigns have indirectly witnessed the effects that this “Dark Matter” has on the Universe. Unfortunately, all attempts to detect it so far have failed, leading scientists to propose some very interesting theories about its nature.

One such theory was offered by the late and great Stephen Hawking, who proposed that the majority of dark matter may actually be primordial black holes (PBH) smaller than a tenth of a millimeter in diameter. But after putting this theory through its most rigorous test to date, an international team of scientists led from the Kavli Institute for the Physics and Mathematics of the Universe (IPMU) has confirmed that it is not.

April 3, 2019April 4, 2019 by Evan Gough

The Wait is Almost Over. We’ll Finally See a Picture of a Black Hole’s Event Horizon on April 10th

This is what scientists at the EHT think they'll see. Image Credit: EHT, ESO

The rumours you’ve heard are true. And if you haven’t heard the rumours, you should check your internet connection.

The Event Horizon Telescope (EHT) Collaboration has set an important press conference for April 10th. They haven’t come right out and said it, but a Media Advisory from the ESO, a partner in the EHT, says they will, “hold a press conference to present a ground-breaking result from the EHT.” If it’s not a black hole, what else would it be?

April 3, 2019April 3, 2019 by David Dickinson

See the Moon Photobomb Saturn in an Amazing Capture

Saturn photobomb — A composite capture of Saturn versus the Moon, minutes before the March 31st occultation. Image credit and copyright: Cory Schmitz, PhotographingSpace.com

Welcome to Saturn, as you’ve probably never seen it. It’s always awe-inspiring to see the clockwork motion of the heavens, transpire in real time. In a slow motion Universe, occultations give us the chance to see the cosmos pull off a celestial hat-trick. This can appear as a split second-type of event—such as when the Moon, a planet or an asteroid winks out a distant star—or transpire as a leisurely affair as the Moon covers, then uncovers the disk of a planet.

April 2, 2019April 2, 2019 by Evan Gough

Ground-Based Telescope Directly Observes the Atmosphere of an Extrasolar Planet, and Sees Swirling Clouds of Iron and Silicates

An artist's illustration of the exoplanet HR8799e. The ESO's GRAVITY instrument on its Very Large Telescope Interferometer made the first direct optical observation of this planet and its atmosphere. Image Credit: ESO/L. Calçada

We’ve finally got our first optical look at an exoplanet and its atmosphere, and boy is it a strange place. The planet is called HR8799e, and its atmosphere is a complex one. HR8799e is in the grips of a global storm, dominated by swirling clouds of iron and silicates.

April 2, 2019April 2, 2019 by Matt Williams

Satellites Watched a Huge Fireball Explode Above the Bering Sea Late Last Year

NASA's MODIS instrument, aboard the Terra satellite, captured this true-color image showing the remnants of a meteor's passage, seen as a dark shadow cast on thick, white clouds on Dec. 18, 2018. Credit: NASA GSFC

When a meteor strike the Earth’s atmosphere, a magnificent (and potentially deadly) explosion is often the result. The term for this is “fireball” (or bolide), which is used to describe exceptionally bright meteor explosions that are bright enough to be seen over a very wide area. A well-known example of this is the Chelyabinsk meteor, a superbolide that exploded in the skies over a small Russian town in February of 2013.

On December 18th, 2018, another fireball appeared in the skies over Russia that exploded at an altitude of about 26 km (16 mi) above the Bering Sea. The resulting debris was observed by instruments aboard the NASA Terra Earth Observation System (EOS) satellite, which captured images of the remnants of the large meteor a few minutes after it exploded.

March 27, 2019November 21, 2021 by Matt Williams

Maybe Self-Replicating Robot Probes are Destroying Each Other. That’s Why We Don’t See Them

SETI's Allen Telescope Array monitor the stars for signs of intelligent life (SETI.org)

During the 1940s, Hungarian-American scientist John von Neumann developed a mathematical theory for how machines could endlessly reproduce themselves. This work gave rise to the idea of “von Neumann probes“, a class of self-replicating interstellar probes (SRPs) that could be used to do everything from exploring the Universe to seeding it with life and intervening in species evolution.

Some have naturally suggested that this be a focus of SETI research, which would entail looking for signs of self-replicating spacecraft in our galaxy. But as is always the case with proposals like these, the Fermi Paradox eventually reasserts itself by asking the age-old question – “Where is everybody?” If there are alien civilizations out there, why haven’t we found any evidence of their SRPs?