"Professor Goddard does not know the relation between action and reaction and the need to have something better than a vacuum against which to react. He seems to lack the basic knowledge ladled out daily in high schools."
--1921 New York Times editorial about Robert Goddard's revolutionary rocket work.

"Correction: It is now definitely established that a rocket can function in a vacuum. The 'Times' regrets the error."
NY Times, July 1969.

— New York Times

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APOD - Sun, 07/06/2025 - 4:00pm


Categories: Astronomy, NASA

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APOD - Sun, 07/06/2025 - 4:00pm

Face-on spiral galaxy NGC 6946 and open star cluster NGC 6939 share


Categories: Astronomy, NASA

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APOD - Sun, 07/06/2025 - 4:00pm

If you know where to look, you can see a thermonuclear explosion from a white dwarf star.


Categories: Astronomy, NASA

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APOD - Sun, 07/06/2025 - 4:00pm

Does the Milky Way always rise between these two rocks?


Categories: Astronomy, NASA

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APOD - Sun, 07/06/2025 - 4:00pm

What do you see when you look into this sky?


Categories: Astronomy, NASA

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APOD - Sun, 07/06/2025 - 4:00pm

It's raining stars.


Categories: Astronomy, NASA

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APOD - Sun, 07/06/2025 - 4:00pm

Why is there a spiral around the North Pole of Mars?


Categories: Astronomy, NASA

Space auction: Sally Ride memorabilia collection sells for $145,000

Space.com - Sun, 07/06/2025 - 11:00am
A collection of more than 50 pieces of memorabilia previously owned by Sally Ride, the first American woman to reach space, sold at auction last week for more than $145,000.
Categories: Astronomy

Why does Mars look purple, yellow and orange in ESA's stunning new satellite image?

Space.com - Sun, 07/06/2025 - 10:01am
Surprising colors and stunning features are captured in a new image of Mars' surface.
Categories: Astronomy

US military cuts climate scientists off from vital satellite sea-ice data

Space.com - Sun, 07/06/2025 - 10:00am
In the latest attack on science by the Trump administration, researchers at the National Snow and Ice Data Center will no longer receive data from a fleet of military satellites.
Categories: Astronomy

How To Use Fusion To Get To Proxima Centauri's Potentially Habitable Exoplanet

Universe Today - Sun, 07/06/2025 - 7:51am

Proxima Centauri b is the closest known exoplanet that could be in the habitable zone of its star. Therefore, it has garnered a lot of attention, including several missions designed to visit it and send back information. Unfortunately, due to technological constraints and the gigantic distances involved, most of those missions only weigh a few grams and require massive solar scales or pushing lasers to get anywhere near their target. But why let modern technological levels limit your imagination when there are so many other options, if still theoretical, options to send a larger mission to our nearest potentially habitable neighbor? That was the thought behind the Master’s Thesis of Amelie Lutz at Virginia Tech - she looked at the possibility of using fusion propulsion systems to send a few hundred kilogram probe to the system, and potentially even orbit it.

Categories: Astronomy

Reviving SETI with High-Energy Astronomy

Universe Today - Sun, 07/06/2025 - 7:51am

What new methods can be developed in the search for extraterrestrial intelligence (SETI)? This is what a recent white paper submitted to the 2025 NASA Decadal Astrobiology Research and Exploration Strategy (DARES) Request for Information (RFI) hopes to address as a pair of researchers from the Breakthrough Listen project and Michigan State University discussed how high-energy astronomy could be used for identifying radio signals from an extraterrestrial technological civilization, also called technosignatures. This study has the potential to help SETI and other organizations develop novel techniques for finding intelligent life beyond Earth.

Categories: Astronomy

Webb Refines the Bullet Cluster's Mass

Universe Today - Sun, 07/06/2025 - 7:51am

One of the most iconic cosmic scenes in the Universe lies nearly 3.8 billion light-years away from us in the direction of the constellation Carina. This is where two massive clusters of galaxies have collided. The resulting combined galaxies and other material is now called the Bullet Cluster, after one of the two members that interacted over several billion years. It's one of the hottest-known galaxy clusters, thanks to clouds of gas that were heated by shockwaves during the event. Astronomers have observed this scene with several different telescopes in multiple wavelengths of light, including X-ray and infrared. Those observations and others show that the dark matter makes up the majority of the cluster's mass. Its gravitational effect distorts light from more distant objects and makes it an ideal gravitational lens.

Categories: Astronomy

Will YR4 Hit the Moon? We Won't Know Until 2028

Universe Today - Sun, 07/06/2025 - 7:51am

Earlier this year, asteroid 2024 YR4 was discovered and found to have a trajectory through the Earth/Moon system in 2032. The world's telescopes focused on the potential threat and downgraded the chance to negligible for the Earth...but it still has a non-zero chance of hitting the Moon. As the asteroid became too dim to continue observing, its Moon impact chance stood at 4%. When will we update this number? Not until it does another close flyby in 2028.

Categories: Astronomy

Old Hubble Space Telescope Photos Unlock the Secret of a Rogue Planet

Universe Today - Sun, 07/06/2025 - 7:51am

Astronomers have made a breakthrough by using 25 year old Hubble images to investigate a potential "rogue planet" drifting through space without a host star. When a brief gravitational microlensing event occurred in 2023, researchers discovered Hubble had photographed the same location in 1997, creating an unprecedented quarter century baseline. Finding no stellar companion in the archival data strengthened evidence for a rogue planet with mass between Earth and Saturn, demonstrating the scientific value of space telescope archives for studying these elusive worlds wandering the Galaxy alone.

Categories: Astronomy

Machine Learning is Surprisingly Good at Simulating the Universe

Universe Today - Sun, 07/06/2025 - 7:51am

Some of the most powerful supercomputers in the world are designed to simulate complex astrophysical processes, like what's happening inside a giant star as it's going supernova. But researchers have developed a new machine learning algorithm that was able to accurately simulate galaxy evolution with fewer computer resources and dramatically more quickly than a supercomputer, which could take years to fully process.

Categories: Astronomy

If Dark Energy is Decreasing, is the Big Crunch Back on the Menu?

Universe Today - Sun, 07/06/2025 - 7:51am

Astronomers once wondered if the Universe might one day collapse in on itself in a Big Crunch, but the discovery of dark energy suggested that the expansion of the Universe would accelerate, removing that possibility. New data from the Dark Energy Spectroscopic Instrument suggests that dark energy might be changing in strength over time, maybe even going negative. If that result holds, are we due for a Big Crunch? And how long would it take?

Categories: Astronomy

High-Speed Gas Clouds Fuel Star Formation in Depleted Galaxies

Universe Today - Sun, 07/06/2025 - 7:51am

How do galaxies like ours continue producing stars long after they should have used up their star-forming gas. Somehow, an external gas source must find its way into the galaxy. New research has found evidence of gas clouds that found their way into a spiral galaxy, likely fueling continued star formation.

Categories: Astronomy

A Star Detonated as a Supernova... Twice

Universe Today - Sun, 07/06/2025 - 7:51am

The beautiful supernova remnant looks a little different from other examples of stars that detonated in the past. And it should, because according to astronomers, the star that met its end exploded twice. It was a white dwarf in its former life, pulling material from a binary companion, creating the perfect conditions for a Type 1a supernova. It accumulated a blanket of helium, which exploded first, triggering a second detonation at the core of the star.

Categories: Astronomy