Hyades for the Holidays
24.12.2012

Recognized since antiquity and depicted on the shield of Achilles according to Homer, stars of the Hyades cluster form the head of the constellation Taurus the Bull. Their general V-shape is anchored by Aldebaran, the eye of the Bull and by far the constellation's brightest star.

Sharpest Ultima Thule
28.02.2019

On January 1, New Horizons swooped to within 3,500 kilometers of the Kuiper Belt world known as Ultima Thule. That's about 3 times closer than its July 2015 closest approach to Pluto.

The Magnetic Field of the Whirlpool Galaxy
20.01.2021

Do magnetic fields always flow along spiral arms? Our face-on view of the Whirlpool Galaxy (M51) allows a spectacularly clear view of the spiral wave pattern in a disk-shaped galaxy. When observed with a radio telescope, the magnetic field appears to trace the arms' curvature.

A Force from Empty Space: The Casimir Effect
3.01.2010

This tiny ball provides evidence that the universe will expand forever. Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to energy fluctuations in the vacuum of empty space.

NGC 3314: When Galaxies Overlap
17.11.2021

Why doesn't the nearby galaxy create a gravitational lensing effect on the background galaxy? It does, but since both galaxies are so nearby, the angular shift is much smaller than the angular sizes of the galaxies themselves.

Tunguska: The Largest Recent Impact Event
2.10.2011

Yes, but can your meteor do this? The most powerful natural explosion in recent Earth history occurred on 1908 June 30 when a meteor exploded above the Tunguska River in Siberia, Russia. Detonating with...

Gamma-Ray Burster
19.03.1997

What and where are the Gamma-Ray Bursters? Since their discovery in the early 1970s, nobody has been able to explain the cause of mysterious flashes of gamma rays that come from seemingly random directions on the sky.

Thackerays Globules
12.06.2012

These are larger dust bunnies than you will find under your bed. Situated in rich star fields and glowing hydrogen gas, these opaque clouds of interstellar dust and gas are so large they might be able to form stars.

Places for OSIRIS REx to Touch Asteroid Bennu
23.12.2019

Where is the best place to collect a surface sample from asteroid Bennu? Launched in 2016, NASA sent the robotic Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) to investigate the 500-meter-across asteroid 101955 Bennu.

Gamma Ray Bursts from the Unknown
27.08.1995

Gamma Ray Bursts (GRBs) pose one of the greatest mysteries of modern astronomy. About once a day, the gamma-ray sky lights up with a spectacular explosion. No one knows what causes these explosions or even how far away they are.