Unusual Silica Rich Soil Discovered on Mars
18.12.2007

You're rolling across Mars when you unexpectedly uncover some unusually light soil. You stop. You turn. You return to inspect the soil and find out it is almost purely silica -- the main ingredient in quartz and glass. Such soil has never been found on Mars before. What created this soil?

Unusual Spiral Galaxy M66
10.08.1996

Spiral galaxy M66 is largest galaxy in the a group known as the Leo Triplet. M66 is somewhat peculiar because of its asymmetric spiral arms. Usually dense waves of gas, dust, and newly formed stars - called spiral density waves - circle a galactic center and create a symmetric galaxy.

Unusual Light Pillars Over Latvia
12.01.2009

What's happening over that town? Close inspection shows these strange columns of light occur over bright lights, and so likely involve falling ice crystals reflecting back these lights. The reason why these pillars...

Jets from Unusual Galaxy Centaurus A
17.01.2021

The jets emanating from Centaurus A are over a million light years long. These jets of streaming plasma, expelled by a giant black hole in the center of this spiral galaxy, light up this composite image of Cen A. Exactly how the central black hole expels infalling matter remains unknown.

Unusual Aurora During Solar Wind Dropout
23.12.1999

On May 10, for some unknown reason, the Solar Wind virtually stopped. Normally our Sun emits a wind of between five and ten energetic particles per cubic centimeter moving outward at about 500 kilometers per second.

Unusual Pits Discovered on Pluto
25.11.2015

Why are there unusual pits on Pluto? The indentations were discovered during the New Horizons spacecraft's flyby of the dwarf planet in July. The largest pits span a kilometer across and dip tens...

Unusual Giant Galaxy NGC 1316
16.08.2000

Can unusual giant galaxy NGC 1316 help calibrate the universe? Quite possibly -- if it turns out this atypical galaxy is composed of typical stars. NGC 1316, pictured above, is most obviously strange because...

Unusual Flashes Toward Globular Cluster M22
3.07.2001

What is causing the unusual flashes behind globular cluster M22? This teaming ball of stars is the brightest globular cluster visible in Earth's northern hemisphere. M22, shown in full in the inset, spans about 50 light years away and lies 8500 light-years toward the constellation of Sagittarius.

Unusual Spherules on Mars
10.02.2004

What are those unusual spherules on Mars? The Mars Opportunity rover has now photographed several unusual nodules on Mars that have a nearly spherical shape. Many times these spherules are embedded in larger rock outcroppings but appear grayer.

Unusual Auroras Over Saturns North Pole
19.11.2008

What's causing this unusual aurora over Saturn? No one is sure. Infrared images by the robotic Cassini spacecraft of the north pole of Saturn have uncovered aurora unlike any other seen previously in our Solar System.