Astronomy Archives

September 12, 2020June 20, 2023 by Matt Williams

Beyond “Fermi’s Paradox” IX: What is the Brief Window Hypothesis?

A case study of the inhabitants of Easter Island served in part as the basis for a mathematical model showing the ways a technologically advanced population and its planet might develop or collapse together. Credit: University of Rochester illustration / Michael Osadciw

Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that we haven’t heard from aliens because intelligent life only survives for so long.

In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?“

This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, there have been several proposed resolutions to his question, which include the possibility that civilizations only have a “Brief Window” with which to communicate with the cosmos before going extinct.

September 11, 2020September 11, 2020 by Evan Gough

Vera Rubin’s Monster 3200-Megapixel Camera Takes its First Picture (in the Lab)

The complete focal plane of the future LSST Camera is more than 2 feet wide and contains 189 individual sensors that will produce 3,200-megapixel images. Crews at SLAC have now taken the first images with it. (Jacqueline Orrell/SLAC National Accelerator Laboratory)

The Vera C. Rubin Observatory has taken another step towards first light, projected for some time in 2022. Its enormous 3200 megapixel camera just took its first picture during lab testing at the SLAC National Accelerator Laboratory. The camera is the largest ever built, and its unprecedented power is the driving force behind the Observatory’s ten year Legacy Survey of Space and Time (LSST).

September 10, 2020September 10, 2020 by Matthew Cimone

A Sunspot, Revealed in Incredible Detail by Europe’s Newly Upgraded GREGOR Telescope

Sunspot image from the newly upgraded GREGOR Telescope

I wear glasses for astigmatism. But, as a stargazer with a visual impediment, turns out I’m in good company. The GREGOR telescope, a solar telescope located at the Teide Observatory in the Canary Islands also suffered from an astigmatism that was recently corrected…to very stellar results.

Opened in 2012, GREGOR is part of a new generation of solar (Sun observing) telescopes. Before 2002, solar scopes were quite small in diameter; under one metre. The Sun is close, and VERY bright, so your telescope doesn’t need to be as wide as those used for deep-space imaging. GREGOR itself is 1.5m (compare that to some of the largest telescopes imaging distant faint objects like the Keck Observatory at 10m. But without the special filters/optics used by a solar scope, a regular telescope staring at the Sun would be destroyed by the Sun’s light). A telescope’s power is often related to its ability to magnify. But just like enlarging a low-resolution photo, the more you magnify, the fuzzier the image becomes (that’s why those scenes in crime shows where they yell ‘enhance!’ and a photo grows to reveal a criminal are not realistic). Ultimately, a telescope’s diameter provides the higher resolution photo. GREGOR is designed to take those high-resolution images of our local Star. How high resolution? Imagine being able to distinguish a 50km wide feature on the Sun from 140 million km away – basically the same as being able to read the text on a coin from a kilometre away.

GREGOR Telescope and redesign components – KIS

September 10, 2020September 10, 2020 by Evan Gough

Jupiter Probably Has 600 Small, Irregular Moons

Europa, Callisto, and Io in front of Jupiter in January 2015. Image Credit: NASA/JPL

The better our technologies get, the better we get at finding objects in space. That’s certainly true of Jupiter and its moons. Prior to Galileo, nobody knew the other planets had moons. Then in 1609/10, as he made improvements to his telescope, he aimed it at the gas giant and eventually found four moons: Io, Europa, Ganymede, and Callisto. Now those four natural satellites also bear his name: the Galilean moons.

Over the centuries since then, and especially in our digital age, astronomical tools and methods kept improving. In particular, wide-field CCD (Charge Coupled Devices) have led to an explosion of astronomical discoveries. In recent years, the confirmed number of Jovian moons has risen to 79. Now, a new study says that there may be 600 small irregular moons orbiting Jupiter.

September 9, 2020September 10, 2020 by Matt Williams

Behold! The Black Hole Collision Calculator!

This image shows two massive black holes in the OJ 287 galaxy. The smaller black hole orbits the larger one, which is also surrounded by a disk of gas. When the smaller black hole crashes through the disk, it produces a flare brighter than 1 trillion stars. Credit: NASA/JPL-Caltech

Black holes have been the subject of intense interest ever since scientists began speculating about their existence. Originally proposed in the early 20th century as a consequence of Einstein’s Theory of General Relativity, black holes became a mainstream subject a few decades later. By 1971, the first physical evidence of black holes was found and by 2016, the existence of gravitational waves was confirmed for the first time.

This discovery touched off a new era in astrophysics, letting people know collision between massive objects (black holes and/or neutron stars) creates ripples in spacetime that can be detected light-years away. To give people a sense of how profound these events are, Álvaro Díez created the Black Hole Collision Calculator (BHCC) – a tool that lets you see what the outcome of a collision between a black hole and any astronomical object would be!

September 8, 2020September 8, 2020 by Evan Gough

The Strange, Misshapen Orbits of Planet-Forming Disks in a Triple-Star System

ALMA images of the planet-forming disk with misaligned rings around triple star system GW Orionis. The image on the right is made with ALMA data taken in 2017 from Bi et al. The image on the left is made with ALMA data taken in 2018 from Kraus et al. Credit: ALMA (ESO/NAOJ/NRAO), S. Kraus & J. Bi; NRAO/AUI/NSF, S. Dagnello

Whatever we grow up with, we think of as normal. Our single solitary yellow star seems normal to us, with planets orbiting on the same, aligned ecliptic. But most stars aren’t alone; most are in binary relationships. And some are in triple-star systems.

And the planet-forming disks around those three-star systems can exhibit some misshapen orbits.

September 8, 2020September 8, 2020 by David Dickinson

Astro-Challenge: Adventures in Daytime Astronomy

It’s one of the stranger observations in ancient literature, and one of the earliest recorded tales of daytime astronomy.

A curious account comes to us from the 1^st century AD Roman scholar Pliny the Elder, concerning the exploits of Greek philosopher Thales of Miletus, who notes that:

“The Sun’s radiance makes the fix’d stars invisible in the daytime, although they are shining as much as in the night, which becomes manifest at a solar eclipse and also when the star is reflected in a very deep well.”

September 8, 2020September 8, 2020 by Andy Tomaswick

Okay, New Idea. Oumuamua is an Interstellar “Dust Bunny”

Artist’s impression of the interstellar object, `Oumuamua, experiencing outgassing as it leaves our Solar System. Credit: ESA/Hubble, NASA, ESO, M. Kornmesser

Explaining the concept of a dust bunny to small children can be quite amusing. No, it’s not actually alive. It’s moving around because of really small currents of wind that we can’t even see. It’s mainly formed out of dead skin and spider webs. No, the spiders don’t actually eat the dead skin. Most of the time.

Now take that same concept of a bunch of particles stuck together, scale it up a few orders of magnitude, and put it in space. Though it’s still not alive, it would be blown by solar radiation rather than the winds. And instead of being made out of skin and spider webs, it could be made up of cometary dust particles. That is what scientists think our first detected visitor from another star might be – an interstellar dust bunny.

September 7, 2020September 7, 2020 by Matt Williams

Extraterrestrial Hunters Figure Out a Way to Expand Their Search for Signals by a Factor of 200

Credit: Breakthrough Listen/Univ. of Machester/Daniëlle Futselaar

In 2015, Russian-American billionaire Yuri Milner established Breakthrough Initiatives, a non-profit organization dedicated to advancing space exploration. Central to this effort is Breakthrough Listen, a ten-year international research program dedicated to the Search for Extraterrestrial Intelligence (SETI) and the largest and most sophisticated effort to find intelligent life beyond Earth to date.

In the past five years, the project has made two major data releases (in the June of 2019 and February of 2020) and announced that it found no signs of alien transmissions from the 1,327 nearest star systems. But thanks to an analytical breakthrough recently proposed by researchers from the University of Manchester, it looks as though Breakthrough Listen’s search efforts could be expanded by a factor of more than 200!

September 7, 2020September 7, 2020 by Evan Gough

Nancy Roman Telescope’s Primary 2.4-Meter Mirror is Ready

Artist's impression of the Nancy Grace Roman Space Telescope, named after NASA’s first Chief of Astronomy. This spacecraft will orbit at SEL2, far from Earth. Credits: NASA

The Nancy Roman Telescope has reached another milestone in its development. NASA has announced that the space telescope’s primary mirror is now complete. The 2.4 meter (7.9 ft) mirror took less time to develop than other mirrors because it wasn’t built from scratch. It’s a re-shaped and re-surfaced mirror that came from the National Reconnaissance Office.