Category: Space & Physics

From Marie Curie to the Demon Core: When Radiation Kills

By Sarah Watts | March 23, 2018 10:04 am
Cherenkov radiation glowing in the core of the Advanced Test Reactor at Idaho National Laboratory. (Credit: Argonne National Laboratory)

Cherenkov radiation glowing in the core of the Advanced Test Reactor at Idaho National Laboratory. (Credit: Argonne National Laboratory)

When we hear the word “radiation,” we tend to think of atomic bombs (like the ones that fell on Hiroshima and Nagasaki), or environmental mishaps like the three-eyed fish living outside Springfield’s nuclear power plant on The Simpsons. But radiation – a term that refers to the transmission of energy through waves and particles – is not always a destructive force.

“The word radiation is a lot broader than people realize,” says Johnathan M. Links, a medical physicist and professor at Johns Hopkins School of Public Health. “When people say radiation, what they usually mean is ionizing radiation, which has sufficient energy to eject electrons from atoms. Non-ionizing radiation doesn’t have that capability, and that’s an important distinction. When you eject electrons from atoms you can break chemical bonds, and that’s what leads to the microscopic and macroscopic damage that radiation causes.” Read More

A Brilliant Life: Stephen Hawking Defied All Odds

By Martin Rees, University of Cambridge | March 14, 2018 9:22 am
stephen-hawking

(Credit: Lwp Kommunikáció/Flickr, CC BY-SA)

Soon after I enrolled as a graduate student at Cambridge University in 1964, I encountered a fellow student, two years ahead of me in his studies, who was unsteady on his feet and spoke with great difficulty. This was Stephen Hawking. He had recently been diagnosed with a degenerative disease, and it was thought that he might not survive long enough even to finish his PhD. But he lived to the age of 76, passing away on March 14, 2018.

It really was astonishing. Astronomers are used to large numbers. But few numbers could be as large as the odds I’d have given against witnessing this lifetime of achievement back then. Even mere survival would have been a medical marvel, but of course he didn’t just survive. He became one of the most famous scientists in the world – acclaimed as a world-leading researcher in mathematical physics, for his best-selling books and for his astonishing triumph over adversity. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts

NASA’s Next Stop: A Space Station Orbiting The Moon

By Korey Haynes | March 13, 2018 3:15 pm
gateway

An artist’s concept of a future orbital moon station. (Credit: Boeing)

The International Space Station is entering its twilight years. As such, NASA is making plans for the space station of the future — one that would orbit the moon.

This new lunar outpost will be smaller and more remote than the ISS — orbing beyond Earth’s protective magnetic field. And the station’s goal would be to serve as a transit hub for deep space missions and exploration past low-Earth orbit, while continuing all the science that can be done in zero gravity. It would also be within easy reach of the lunar surface. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: space exploration

Space Wars Will Look Nothing Like Star Wars

By Nathaniel Scharping | February 15, 2018 12:22 pm
(Credit: Adam Hartman/U.S. Navy)

(Credit: Adam Hartman/U.S. Navy)

Darting spaceships. Dazzling lasers. Fiery explosions. All of these are things that a war in space would almost certainly not involve.

Ever since Star Wars, the public has been fascinated by the visuals of space conflict — it’s futuristic, thrilling, and cosmic battles are bereft of the gore that so often accompanies terrestrial conflict. And ever since Sputnik, humans have been putting things into space, pieces of technology that are now vital cogs in the machinery of society. We rely on satellites for everything from credit card transactions to mapping apps. The military needs satellites for communication, as well as for the imaging that lets them keep an eye on friend and foe alike.

Therefore, forget about the Death Star, this amalgamation of blinking hardware floating in Earth’s orbit would be target numero uno. But would it be wise to pull the trigger? Read More

CATEGORIZED UNDER: Space & Physics, Technology

Pulsars Could Guide Autonomous Spacecraft of the Future

By Amber Jorgenson | January 16, 2018 10:45 am
pulsar-nasa

A pulsar (pink, center) at the center of the galaxy Messier 82. (Credit: NASA)

Although it’s possible for space missions to communicate data with Earth, the process is anything but fast. Voyager 1, for example, takes about 19 hours to send a signal back to Earth, and that lag only increases as the spacecraft gets further away.  For truly long-term, deep space missions, the significant amount of time it takes to send a signal isn’t going to cut it. The spacecraft will need to adjust its own trajectory without relying on ground navigation. That’s where pulsars come in.

Last week, a group of NASA engineers showed that fully autonomous space navigation is possible through the use of X-rays, a discovery that could overhaul our approach to deep space travel. The X-ray guidance system was successfully tested during the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) experiment. Using  pulsars timed down to the millisecond, the test craft relied on X-rays to pinpoint the location of a space object moving at thousands of miles per hour. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: space exploration

A Day Isn’t Actually 24 Hours And Other Weird Solstice Facts

By Eric Betz | December 21, 2017 3:21 pm
(Credit: Shutterstock)

(Credit: Shutterstock)

Those of us brave souls who inhabit America’s northern climes know that it’s not the cold that brings on the winter blues. You go to work and it’s dark. You leave work and it’s dark. The sun? What’s that?

Indeed, as I post this at 3:30 p.m., the sun is already nearing the horizon. The sky above is dark. Today — the Winter Solstice — the sun will set at 4:20 p.m. here in Milwaukee. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts

Satellite ‘License Plates’ Could Prevent a Disaster in Low Earth Orbit

By David Palmer | December 18, 2017 1:44 pm

space-junk

Space may look vast, but it’s actually pretty crowded near Earth.

As of a couple of years ago, more than 1,300 active satellites orbited Earth, in addition to tens of thousands of dead satellites, discarded rockets and other bits and pieces that have accumulated in space in the 60 years since Sputnik, ranging in size from softballs to school buses. When we turn on a new radar in a few years that can see even smaller pieces, we are going to see millions of them. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: space junk

The Mysterious Asteroid Behind the Year’s Best Meteor Shower

By Eric Betz | December 13, 2017 10:35 am
Geminids over ESO’s Paranal Observatory in Chile in 2013. Image: ESO/G. Lombardi

Geminids over ESO’s Paranal Observatory in Chile in 2013. (Credit: ESO/G. Lombardi)

Step outside after dark this week and you can watch chunks of an asteroid burn up in Earth’s atmosphere. Behold, the Geminid meteor shower, which is renowned as the year’s best.

At peak Geminids, you could catch a shooting star every minute, and this year the moon won’t be bright enough to foul the show. That main action arrives just past 9 p.m. local time Wednesday and lasts until dawn. “The Geminids are rich in fireballs and bright meteors so that makes them very good to observe,” says Bill Cooke, who runs NASA’s Meteoroid Environment Office. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts

The Atomic Age: Far More Than Explosions and Electricity

By Carl Engelking | December 1, 2017 6:53 pm
Scientists witness the first self-sustained fission reaction.

Scientists witness the first nuclear fission chain reaction. (Credit: John Cadel/Chicago History Museum)

Seventy-five years ago, the world officially entered the Atomic Age. Henceforth, it would never be the same.

In October 1942, as part of the Manhattan Project, Enrico Fermi assembled a crack team of physicists for an urgent, top-secret government mission: Conduct the first man-made, self-sustaining nuclear chain reaction to prove it was indeed possible to build an atomic weapon—and do it before the Germans. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts

Close Calls Nearly Doomed These Space Missions

By K. N. Smith | December 1, 2017 2:21 pm
mariner-10

The Mariner 10 spacecraft experienced several problems, but nonetheless accomplished its goals, thanks to a smart mission team and some quick fixes. (Credit: NASA)

A tiny problem can have huge consequences for a space mission. Sometimes a huge endeavor hinges on the smallest detail — three seconds’ worth of fuel, an engineer’s stubbornness, a speck of paint, or a 1.3-millimeter calibration.

When surprise glitches revealed themselves after launch, it took massive efforts to save the missions that gave us a closer look at Mercury, a tour of the outer solar system, our only glimpse of Titan’s surface, and an incredible view of the early universe. But even with hundreds of people putting in months of work, a few of these missions only succeeded by a razor-thin margin. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts
NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

The Crux

A collection of bright and big ideas about timely and important science from a community of experts.
ADVERTISEMENT

See More

ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Collapse bottom bar
+