Astronomy Archives

June 15, 2023June 15, 2023 by Alan Boyle

How Science Fiction Sparked Our Flights to the Final Frontier

Illustration from Jules Verne's "From the Earth to the Moon" — Jules Verne envisioned building a projectile for space travel in "From the Earth to the Moon." (E.A. Bayard via Scribner, Armstrong / Smithsonian)

The commercial spaceflight revolution didn’t begin with Elon Musk. Or with Jeff Bezos, or Richard Branson, or any of the other billionaires who’ve spent a fortune on the final frontier over the past 20 years.

Would you believe it began with Jules Verne in the 1860s?

That’s the perspective taken by Jeffrey Manber, one of the pioneers of the 21st-century spaceflight revolution, in a book tracing the roots of private-sector spaceflight to the French novelist.

“The first realistic steps taken in rocket development were because of a French science-fiction book,” Manber says in the latest episode of the Fiction Science podcast. “And that’s an underlying theme, in that we really needed a commercial ecosystem to get going. It’s not a government decree.”

https://radiopublic.com/fiction-science-GAxyzK/s1!443fb

June 15, 2023June 16, 2023 by David Dickinson

Startup PLD Space to Launch Europe’s First Reusable Rocket

PLD Space could launch its suborbital Miura-1 rocket this month.

Update: Game on… PLD Space has announced that they will attempt to launch Miura-1 tonight. The live webcast starts on June 17th (Saturday local time) at 1:00 AM Central European Time (11:00 PM Friday night on June 16th Universal Time, and 7:00 PM Eastern Daylight Saving Time), and the eight hour launch window begins at 2:00 AM CET/00:00UT/8:00 PM EDT.

A small space startup with big ambitions may be joining the private spaceflight club soon. This summer, Elche Spain-based PLD Space is set to carry out the first test launch of their single stage, suborbital Miura-1 rocket.

June 14, 2023June 14, 2023 by Matt Williams

A Day on Earth Used to Only Be 19 Hours

A full disk view of the Earth, courtesy of Meteosat-I 1. Credit: ESA/Meteosat

On Earth, a single solar day lasts 24 hours. That is the time it takes for the Sun to return to the same place in the sky as the day before. The Moon, Earth’s only natural satellite, takes about 27 days to complete a single circuit around our planet and orbits at an average distance of 384,399 km (~238,854.5 mi). Since time immemorial, humans have kept track of the Sun, the Moon, and their sidereal and synodic periods. To the best of our knowledge, the orbital mechanics governing the Earth-Moon system have been the same, and we’ve come to take them for granted.

But there was a time when the Moon orbited significantly closer to Earth, and the average day was much shorter than today. According to a recent study by a pair o researchers from China and Germany, an average day lasted about 19 hours for one billion years during the Proterozoic Epoch – a geological period during the Precambrian that lasted from 2.5 billion years to 541 million years ago. This demonstrates that rather than gradually increasing over time (as previously thought), the length of a day on Earth remained constant for an extended period.

June 14, 2023June 14, 2023 by Evan Gough

A White Dwarf is Starting to Crystallize into Diamond

An artist’s impression of crystallization in a white dwarf star. The twho known white dwarf pulsars may have interiors like this. Image credit: Mark Garlick / University of Warwick.

White dwarfs are the stellar remnants of stars like our Sun. They’re strange objects, and astrophysicists think their cores can crystallize into enormous diamonds. But they need to find more of these strange objects, and they need to know their ages, to understand how and when it happens.

June 13, 2023June 13, 2023 by Paul M. Sutter

Without Ozone, the Earth Might Get a Lot Colder

Clouds trace out the islands of the Caribbean Sea in this photo taken by an astronaut from inside the Cupola on the International Space Station. Credit NASA/NASA Earth Observatory.

The evolution of Earth’s climate contains many components. And new research has shown just how critical the ozone layer is to the surface temperature of the Earth. Without an ozone layer, our planet would be 3.5 Kelvin cooler.

June 12, 2023June 13, 2023 by Paul M. Sutter

Meet Annie Jump Cannon, the “Harvard Computer” that Brought Order Out of Chaos

These Hubble Space Telescope images showcase two of the 19 galaxies analyzed in a project to improve the precision of the universe's expansion rate, a value known as the Hubble constant. The color-composite images show NGC 3972 (left) and NGC 1015 (right), located 65 million light-years and 118 million light-years, respectively, from Earth. The yellow circles in each galaxy represent the locations of pulsating stars called Cepheid variables. Credits: NASA, ESA, A. Riess (STScI/JHU)

In the early 20th century our understanding of stars was a complete and total disaster. It took the genius of Annie Jump Cannon, who was hired as a human computer, to create some order out of the chaos.

June 12, 2023June 12, 2023 by Carolyn Collins Petersen

Astronomers Have Figured Out Clever Tricks to Reduce the Impact of Satellite Trails

A long-exposure image of the Orion Nebula with a total exposure time of 208 minutes showing satellite trails in mid-December 2019. Credit: A. H. Abolfath

A clear sky is a prerequisite for most astronomers imaging the cosmos. However, with the proliferation of satellite trails, astronomers see a lot more streaks in their images. That’s particularly true for people using professional ground-based and orbiting telescopes. When Hubble Space Telescope opened its eye on the sky, there were less than 500 satellites orbiting our planet. Now, there are nearly 8,000 of them, leaving their mark across the sky.

June 12, 2023June 12, 2023 by Evan Gough

The Tarantula Nebula Shouldn’t Be Forming Stars. What’s Going On?

30 Doradus, also known as the Tarantula Nebula, is a region in the Large Magellanic Cloud. Streamlines show the magnetic field morphology from SOFIA HAWC+ polarization maps. These are superimposed on a composite image captured by the European Southern Observatory’s Very Large Telescope and the Visible and Infrared Survey Telescope for Astronomy. Credit: Background: ESO, M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit. Streamlines: NASA/SOFIA

The Tarantula Nebula is a star formation region in the Large Magellanic Cloud (LMC). Tarantula is about 160,000 light-years away and is highly luminous for a non-stellar object. It’s the brightest and largest star formation region in the entire Local Group of galaxies.

But it shouldn’t be.

June 12, 2023June 12, 2023 by Scott Alan Johnston

These are the Fastest Stars in the Galaxy

Artist concept showing a hypervelocity star escaping our galaxy. Credit: NASA, ESA, and G. Bacon (STScI)

Until recently, there were only ten known stars on trajectories that will allow them to escape the Milky Way Galaxy, thrown astray by powerful supernova explosions. A new study using data from ESA’s Gaia survey this June has revealed an additional six runaways, two of which break the record for the fastest radial velocity of any runaway star ever seen: 1694 km/s and 2285 km/s.

June 11, 2023June 11, 2023 by Paul M. Sutter

We Might Soon Detect the Gravitational Waves from Dying Stars

Artist's impression of a supernova remnant. Credit: ESA/Hubble

Researchers have discovered an exciting new source of gravitational waves. They are the remnants left over from a supernova explosion, and they may just reveal the secrets to how those explosions work.