Starlink Satellite Trails over Brazil
10.12.2019

What are those streaks over the horizon? New Starlink satellites reflecting sunlight. SpaceX launched 60 Starlink communication satellites in May and 60 more in November. These satellites and thousands more are planned by communications companies in the next few years that may make streaks like these relatively common.

Highlights of the Summer Sky
5.06.2017

What's up in the sky this summer? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early summer sky events fan out toward the left, while late summer events are projected toward the right.

A Sonic Boom
21.02.2001

Many people have heard a sonic boom, but few have seen one. When an airplane travels at a speed faster than sound, density waves of sound emitted by the plane cannot precede the plane, and so accumulate in a cone behind the plane.

The Missing Craters of Asteroid Itokawa
9.02.2014

Where are the craters on asteroid Itokawa? Missing -- unexpectedly. The Japanese robot probe Hayabusa approached the Earth-crossing asteroid in 2005 and returned pictures showing a surface unlike any other Solar System body yet photographed -- a surface possibly devoid of craters.

Moondog Night
10.12.2014

In this night scene from the early hours of November 14, light from a last quarter Moon illuminates clouds above the mountaintop domes of Kitt Peak National Observatory near Tucson, Arizona. Bright Jupiter...

On the Trail of 2008 TC3
8.11.2008

On October 7, the early dawn over northern Sudan revealed this twisted, high altitude trail. Captured in a video frame, the long-lasting persistent train is from the impact of a small asteroid cataloged as 2008 TC3.

Comets and Bright Star
6.01.2016

This timely, telescopic, two panel mosaic spans about 10 full moons across planet Earth's predawn skies. Recorded as the year began from Tenerife, Canary Islands, near the top of the frame are the faint coma and tail of Comet Borrelly (P/19).

Aurora In West Texas Skies
15.09.2000

The aurora borealis, or northern lights, are not a common sight in the southwestern United States. But a strong solar coronal mass ejection in early August triggered geomagnetic storms and aurora which were widely reported, even under west Texas skies.

Jets from Comet Churyumov Gerasimenko
2.02.2015

Where do comet tails come from? Although it is common knowledge that comet tails and comas originate from comet nuclei, exactly how that happens is an active topic of research. One of the best...

Curiosity at Teal Ridge
8.08.2019

Part of a 360 degree panorama, this view looks out from the Mars rover Curiosity's current location on the Red Planet dubbed Teal Ridge. The mosaicked scene was captured by the rover's Mastcam on Earth calendar date June 18, 2019.