Welcome to Perihelion
4.01.2025

Earth's orbit around the Sun is not a circle, it's an ellipse. The point along its elliptical orbit where our fair planet is closest to the Sun is called perihelion. This year perihelion is today, January 4, at 13:28 UTC, with the Earth about 147 million kilometers from the Sun.

Double Asteroid 90 Antiope
1.11.2000

This eight-frame animation is based on the first ever images of a double asteroid! Formerly thought to be a single enormous chunk of rock, asteroid 90 Antiope resides in the solar system's main asteroid belt between Mars and Jupiter.

Island Universe, Cosmic Sand
23.08.2002

On August 13, while counting Perseid meteors under dark, early morning Arizona skies, Rick Scott set out to photograph their fleeting but fiery trails. The equipment he used included a telephoto lens and fast color film. After 21 pictures he'd caught only two meteors, but luckily this was one of them.

Hubble Floats Free
6.03.1997

Why put observatories in space? Most telescopes are on the ground. On the ground, you can deploy a heavier telescope and upgrade it more easily. The trouble is that Earth-bound telescopes must look through the Earth's atmosphere.

The Flight Of Helios
22.07.2007

An example of solar-powered flight, NASA's Helios aircraft flew almost one hundred years after the Wright brothers' historic flight on December 17, 1903. Pictured here at 10,000 feet in in skies northwest of Kauai, Hawaii in August 2001, the remotely piloted Helios is traveling at about 25 miles per hour.

An Apollo 15 Panorama: Astronaut Exploring
30.11.2008

What would it be like to explore the Moon? NASA's Apollo missions gave humans just this chance in the late 1960s and early 1970s. In particular, the Apollo 15 mission was dedicated to better understanding the surface of the Moon by exploring mountains, valleys, maria, and highlands.

Venus in the Moon
4.12.2008

On December 1, bright planets Venus and Jupiter gathered near the young crescent Moon, an inspiring celestial scene in early evening skies around the world. But from some locations the Moon actually passed in front of Venus, interrupting the tight grouping with a lunar occultation.

Betelgeuse Resolved
5.08.2009

The sharpest image ever of Betelgeuse shows a mammoth star that is slowly evaporating. Betelgeuse (sounds a lot like "beetle juice"), also known as Alpha Orionis, is one of the largest and brightest stars known. The star is a familiar orange fixture easily visible to the unaided eye toward the constellation of Orion.

Seasonal Dark Streaks on Mars
8.08.2011

What is causing these dark streaks on Mars? A leading hypothesis is flowing -- but quickly evaporating -- water. The streaks, visible in dark brown near the image center, appear in the Martian spring and summer but fade in the winter months, only to reappear again the next summer.

Evidence of an Active Volcano on Venus
14.01.2020

Are volcanoes still active on Venus? More volcanoes are known on Venus than Earth, but when Venusian volcanoes last erupted is not directly known. Evidence bolstering very recent volcanism on Venus has recently been uncovered, though, right here on Earth.