A nebula that extends its hand into space

The Gum Nebula is an emission nebula almost 1400 light-years away. It's home to an object known as "God's Hand" among the faithful. The rest of us call it CG 4.

Ritacuba Blanco: death of a Colombian glacier

Just a few months ago, the Colombian mountain peak of Ritacuba Blanco was covered in an unbroken layer of white ice and snow, just as it had been for as long as anyone can remember.

The Great Observatory for Long Wavelengths (GO-LoW) proposal

Humankind has never before seen the low frequency radio sky. It is hidden from ground-based telescopes by the Earth's ionosphere and challenging to access from space with traditional missions because the long wavelengths ...

NASA scientists gear up for solar storms at Mars

In the months ahead, two of NASA's Mars spacecraft will have an unprecedented opportunity to study how solar flares—giant explosions on the sun's surface—could affect robots and future astronauts on the Red Planet.

Webb captures iconic Horsehead Nebula in unprecedented detail

The NASA/ESA/CSA James Webb Space Telescope has captured the sharpest infrared images to date of one of the most distinctive objects in our skies, the Horsehead Nebula. These observations show a part of the iconic nebula ...

Mapping the Milky Way's magnetic field in 3D

We are all very familiar with the concept of the Earth's magnetic field. It turns out that most objects in space have magnetic fields but it's quite tricky to measure them. Astronomers have developed an ingenious way to measure ...

Scientists capture X-rays from upward positive lightning

Globally, lightning is responsible for over 4,000 fatalities and billions of dollars in damage every year; Switzerland itself weathers up to 150,000 strikes annually. Understanding exactly how lightning forms is key for reducing ...

TESS finds its first rogue planet

Well over 5,000 planets have been found orbiting other star systems. One of the satellites hunting for them is TESS, the Transiting Exoplanet Survey Satellite. Astronomers using TESS think they are made a rather surprising ...

page 1 from 40

Radiation

In physics, radiation describes any process in which energy emitted by one body travels through a medium or through space, ultimately to be absorbed by another body. Non-physicists often associate the word with ionizing radiation (e.g., as occurring in nuclear weapons, nuclear reactors, and radioactive substances), but it can also refer to electromagnetic radiation (i.e., radio waves, infrared light, visible light, ultraviolet light, and X-rays) which can also be ionizing radiation, to acoustic radiation, or to other more obscure processes. What makes it radiation is that the energy radiates (i.e., it travels outward in straight lines in all directions) from the source. This geometry naturally leads to a system of measurements and physical units that are equally applicable to all types of radiation.

This text uses material from Wikipedia, licensed under CC BY-SA