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NASA is preparing a mission to deliberately smash a spacecraft into an asteroid — a test run should humanity ever need to stop a giant space rock from wiping out life on Earth.

It may sound like science fiction, but the DART (Double Asteroid Redirection Test) is a real proof-of-concept experiment, blasting off at 10:21pm Pacific Time Tuesday (11:51am IST Wednesday) aboard a SpaceX rocket from Vandenberg Space Force Base in California.

The goal is to slightly alter the trajectory of Dimorphos, a “moonlet” around 525 feet (160 metres, or two Statues of Liberty) wide that circles a much larger asteroid called Didymos (2,500 feet in diameter). The pair orbit the Sun together.

Impact should take place in the fall of 2022, when the binary asteroid system is 6.8 million miles (11 million kilometres) from Earth, almost the nearest point they ever get.

“What we’re trying to learn is how to deflect a threat,” NASA’s top scientist Thomas Zuburchen said of the $330 million (roughly Rs. 2,460 crore) project, the first of its kind.

To be clear, the asteroids in question pose no threat to our planet.

But they belong to a class of bodies known as Near-Earth Objects (NEOs), which approach within 30 million miles.

NASA’s Planetary Defense Coordination Office is most interested in those larger than 460 feet in size, which have the potential to level entire cities or regions with many times the energy of average nuclear bombs.

There are 10,000 known near-Earth asteroids 460 feet in size or greater, but none has a significant chance to hit in the next 100 years. One major caveat: scientists think there are still 15,000 more such objects waiting to be discovered.

15,000mph kick

Planetary scientists can create miniature impacts in labs and use the results to create sophisticated models about how to divert an asteroid — but models are always inferior to real world tests.

Scientists say the Didymos-Dimorphos system is an “ideal natural laboratory,” because Earth-based telescopes can easily measure the brightness variation of the pair and judge the time it takes the moonlet to orbit its big brother.

Since the current orbit period is known, the change will reveal the effect of the impact, scheduled to occur between September 26 and October 1, 2022.

What’s more, since the asteroids’ orbit never intersects our planet, they are thought safer to study.

The DART probe, which is a box the size of a large fridge with limousine-sized solar panels on either side, will slam into Dimorphos at just over 15,000 miles an hour.

Andy Rivkin, DART investigation team lead, said that the current orbital period is 11 hours and 55 minutes, and the team expects the kick will shave around 10 minutes off that time.

There is some uncertainty about how much energy will be transferred by the impact, because the moonlet’s internal composition and porosity are not known.

The more debris that’s generated, the more push will be imparted on Dimorphos.

“Every time we show up at an asteroid, we find stuff we don’t expect,” said Rivkin.

The DART spacecraft also contains sophisticated instruments for navigation and imaging, including the Italian Space Agency’s Light Italian CubeSat for Imaging of Asteroids (LICIACube) to watch the crash and its after-effects.

“The CubeSat is going to give us, we hope, the shot, the most spectacular image of DART’s impact and the ejecta plume coming off the asteroid. That will be a truly historic, spectacular image,” said Tom Statler, DART program scientist.

Nuclear blasts

The so-called “kinetic impactor” method isn’t the only way to divert an asteroid, but it is the only technique ready to deploy with current technology.

Others that have been hypothesised include flying a spacecraft close by to impart a small gravitational force.

Another is detonating a nuclear blast close by — but not on the object itself, as in the films Armageddon and Deep Impact — which would probably create many more perilous objects.

Scientists estimate 460-foot asteroids strike once every 20,000 years.

Asteroids that are six miles or wider — such as the one that struck 66 million years ago and led to the extinction of most life on Earth, including the dinosaurs — occur around every 100-200 million years.

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Hubble finds missing globular cluster in Milky Way’s crowded stellar halo

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July 5, 2025

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Hubble finds missing globular cluster in Milky Way’s crowded stellar halo

A striking new image captured by NASA’s Hubble Space Telescope has shed light on an underexplored gatekeeper of our galactic neighbours’ achievements and tragedies. Adorned with multi-hued stars, the spherical cluster glitters amid the expanse of stars in our Milky Way galaxy. This type of globular cluster is a very dense grouping of stars — about the same mass as 100,000 suns — that orbit all around the centre of their galaxy. Stars in a cluster are typically roughly the same age, as they formed from the same collapsing gas cloud. In this new view, stars show up in temperatures indicated in red and blue colours: red for colder and blue for hotter stars.

Hubble Maps Forgotten Star Cluster ESO 591-12 to Uncover Milky Way’s Ancient Stellar Secrets

As per a report from NASA’s Hubble team, ESO 591-12 was imaged during the Hubble Missing Globular Clusters Survey—an initiative targeting 34 Milky Way globular clusters that had never been observed by the space telescope. The aim is to construct a comprehensive database of the ages, distances, and stellar populations of all the galaxy’s known globular clusters and star formations. However, it has always been tough for telescopes on Earth to pick out individual stars in these densely populated regions, so Hubble’s high resolution has done much to finally be able to track the movements of stars to unlock their histories and formation.

The ESO 591-12 data are part of an ongoing study to improve knowledge of the formation and evolution of globular clusters in the galaxy’s bulge and halo. These star clusters are cosmic fossils that have preserved cosmic conditions from the primordial universe. Their work helps build a fuller narrative of the evolution of the Milky Way and how it has changed over billions of years.

This new image is a further example of how advanced space-based observing facilities are helping astronomers to excavate the contents of the dark and dusty skeleton cloaking the Milky Way and sculpt a better understanding of not only the universe’s evolution but also that of our cosmic home.
Each one tells part of the astronomical story, and Hubble is digging out new chapters to enrich the tale, such as probing data for clusters as much as ESO 591-12, which have been mostly neglected until now. This finding adds to our knowledge of the early universe by shining a spotlight on something that was in plain sight.

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Very Massive Stars Blow Away Outer Layers in Powerful Winds Before Black Hole Collapse

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Massive stars shed extreme mass before collapsing into black holes

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July 5, 2025

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Massive stars shed extreme mass before collapsing into black holes

New research indicates that the most monstrously huge stars — those more than 100 times as massive as the sun — shed at least 20 times more matter before they collapse than previously thought to do so as they cool off to become black holes. These stars blow off a significant portion of their outer layers in quite powerful stellar winds over the brief but intense course of their lives, leaving behind low masses at the end. One benefit of this extreme mass loss is that it can account for observed strangeness in stars such as those in the Tarantula Nebula, providing new information on stellar evolution, black hole formation, and sources of gravitational waves.

Hurricane-like Stellar Winds Explain Extreme Mass Loss in Universe’s Most Massive Stars

As per a report from Space.com, researchers used sophisticated models and observations to learn that very massive stars give off winds so powerful they act more like hurricanes than gentle solar breezes. Their results agree very well with observations of WNh-type Wolf-Rayet stars in the Tarantula Nebula, which are hotter and more compact than would be expected by standard models. The improved models explain the very high temperatures at the surface and the stability of hydrogen, which address previous challenges.

One key subject in this study is R136a1 — the most massive known star — with a mass up to 230 times that of the sun. The researchers suggested that it either formed as a single star of around 200 solar masses or as a binary star system where the two stars had a combined mass of about 200 solar masses. In both such cases, the star must have lost a huge amount of mass early in its life, so the findings would call into question how it is that massive stars can live long enough to leave such a wreckage in the Large Magellanic Cloud.

The implications extend to black hole formation as well. More massive stellar winds erode more mass, resulting in the production of smaller black holes and decreasing the chances of creating elusive intermediate-mass black holes. This revision also enhances the matches of the model with the observed gravitational wave signal of a coalescing black hole binary.

Although the models are restricted to stars in the Tarantula Nebula, the researchers stress that in order for their findings to be considered universal, it is important to understand stars in different chemical environments as well. The results not only reshape predictions of black hole populations but may also adjust our understanding of how the most massive stars in the universe live — and die.

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New Interstellar Comet 3I/ATLAS Speeds Through Solar System

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Astronomers Capture First-Ever Image of a Dead Star That Exploded Twice in Rare Supernova Event

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July 5, 2025

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Astronomers Capture First-Ever Image of a Dead Star That Exploded Twice in Rare Supernova Event

For the first time, a team of astronomers has captured a clear image of a white dwarf star that exploded not just once, but twice, as a Type Ia supernova — a “double-detonation” that scientists hadn’t thought possible until now. The extraordinary observation could revise our long-held notions of how stars die, suggesting that some stars can explode as supernovas without ever crossing the Chandrasekhar limit, the minimum mass normally thought necessary for such an explosion. The astronomers employed the Very Large Telescope’s MUSE instrument to zoom in on the four-century-old supernova remnant SNR 0509-67.5, which sits 60,000 light-years away in the constellation Dorado, revealing evidence of two separate blasting catastrophes in its construction.

First Visual Proof Shows White Dwarfs Can Explode Twice Without Reaching Chandrasekhar Limit

As the researchers report on July 2 in Nature Astronomy, the team found a distinctive “fingerprint” in the debris of SNR 0509-67.5 in the Large Magellanic Cloud that the models predicted. White dwarfs—which are the dead stage of sun-like stars—usually blow up into Type Ia supernovas after they hit the Chandrasekhar limit by stealing matter from a neighbouring star.

However, this finding shows that the detonation can be launched at an earlier time. The explosion is likely to have a two-step origin, the team argues, with the initial blast being generated when an unstable layer of helium that the star had acquired exploded on its surface; the resulting shock wave then drove a second and main detonation.

“This physical proof of a double-detonation not only helps solve a long-standing mystery of what causes these explosions, but it represents the most visually compelling evidence for this origin.” Priyam Das, University of New South Wales, team leader and author.

Something is happening to Type Ia supernovas, the “standard candles” used to measure cosmic distances, because their brightness doesn’t fluctuate. But they have long mystified scientists with how they explode. Until this discovery, an explosion white dwarf that didn’t surpass the Chandrasekhar limit was only considered in theory.

This fresh visual evidence for the double detonation model further informs our knowledge of stellar evolution and also informs how we should interpret light from distant supernovas. More than its scientific implications, its discovery adds a colourful new page to the story of dying stars — stars that, as it now appears, will not go gently into that night but will light up the sky twice over in fantastic fireworks before vanishing from the cosmos.

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