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    Category Astronomy/Space

    Quasars don’t last long—so how do they get so massive?

    May 12, 2025, Categories  Astronomy/Space

    artist-quasar.jpeg
    Artist’s illustration of a quasar. (Credit : NASA)

    Quasars represent some of the most luminous and energetic phenomena in the universe. These distant powerhouses are driven by supermassive black holes—colossal gravitational engines with masses millions to billions of times that of our sun—which actively devour surrounding matter at incredible rates.

    As gas, dust, and stellar material spiral inward through an accretion disk superheated to millions of degrees, this matter releases tremendous energy across the electromagnetic spectrum before crossing the event horizon. The resulting emissions can outshine entire galaxies despite originating from a region no larger than our solar system.

    The discovery of billion-solar-mass black holes in distant quasars challenges conventional gr...

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    Hubble pinpoints roaming massive black hole

    May 9, 2025, Categories  Astronomy/Space

    Six-panel illustration marked "Artist's Concept." The upper left panel shows the silhouette of supermassive black hole that is adrift inside a galaxy. The middle upper panel shows a yellow star drifting near the black hole. The three following panels show the star being shredded in bright white concentric streamers followed by a white explosion. the bottom right panel is an external view of the galaxy showing a bright white star-like object that is the site if the explosion as viewed in X-rays and visible light.
    This six-panel illustration of a tidal disruption event around a supermassive black hole shows the following: 1) A supermassive black hole is adrift inside a galaxy, its presence only detectable by gravitational lensing; 2) A wayward star gets swept up in the black hole’s intense gravitational pull; 3) The star is stretched or “spaghettified” by gravitational tidal effects; 4) The star’s remnants form a disk around the black hole; 5) There is a period of black hole accretion, pouring out radiation across the electromagnetic spectrum, from X-rays to radio wavelengths; and 6) The host galaxy, seen from afar, contains a bright flash of energy that is offset from the galaxy’s nucleus, where an even more massive black hole dwells.
    Artwork: NASA, ESA, STScI, Ralf Crawford (STScI)

    Like a scene...

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    Spacecraft can ‘brake’ in space using drag − advancing craft agility, space safety and planetary missions

    May 8, 2025, Categories  Astronomy/Space

    When you put your hand out the window of a moving car, you feel a force pushing against you called drag. This force opposes a moving vehicle, and it’s part of the reason why your car naturally slows to a stop if you take your foot off the gas pedal. But drag doesn’t just slow down cars.

    Aerospace engineers are working on using the drag force in space to develop more fuel-efficient spacecraft and missions, deorbit spacecraft without creating as much space junk, and even place probes in orbit around other planets.

    Space is not a complete vacuum − at least not all of it. Earth’s atmosphere gets thinner with altitude, but it has enough air to impart a force of drag on orbiting spacecraft, even up to about 620 miles (1,000 kilometers).

    As an aerospace engineering professor, I st...

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    SPHEREx space telescope begins capturing entire sky

    May 6, 2025, Categories  Astronomy/Space

    NASA’s SPHEREx mission is observing the entire sky in 102 infrared colors, or wavelengths of light not visible to the human eye. This image shows a section of sky in one wavelength (3.29 microns), revealing a cloud of dust made of a molecule similar to soot or smoke.

    Launched on March 11, NASA’s SPHEREx space observatory has spent the last six weeks undergoing checkouts, calibrations, and other activities to ensure it is working as it should. Now it’s mapping the entire sky—not just a large part of it—to chart the positions of hundreds of millions of galaxies in 3D to answer some big questions about the universe.

    On May 1, the spacecraft began regular science operations, which consist of taking about 3,600 images per day for the next two years to provide new insights about the...

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