The Earth and Moon Planetary System
15.10.2001

How similar in size are the Earth and the Moon? A dramatic visual answer to this question is found by combining photographs taken by the Mariner 10 spacecraft that headed out toward Venus and Mercury in 1973.

Planetary Systems Now Forming in Orion
7.12.1996

How do planets form? Astronomers are finding out by studying one of the most interesting of all astronomical nebulae known, the Great Nebula in Orion. Insets to above mosaic show several planetary systems in formation. The bottom left insert shows the relative size of our own Solar System. The Orion Nebula contains many stellar nurseries.

HD 10180: Richest Yet Planetary System Discovered
25.08.2010

Do other rich planetary systems exist? Our Solar System has the most planets of any known star, most probably because it is so hard to detect planets around other stars. Sensitive measurements, though, have...

Lalande 21185: The Nearest Planetary System?
19.10.1996

What's the closest extrasolar planetary system? It may well be planets of the dim red dwarf star cataloged as Lalande 21185 -- a mere 8 light years distant. This star is too faint to be seen by the naked eye and its planets have not been imaged directly.

The Kepler 90 Planetary System
18.12.2017

Do other stars have planetary systems like our own? Yes -- one such system is Kepler-90. Cataloged by the orbiting Kepler satellite, an eighth planet has now been discovered giving Kepler-90 the same number of known planets as our Solar System.

Planetary Systems Now Forming in Orion
22.12.2009

How do planets form? To help find out, the Hubble Space Telescope was tasked to take a detailed look at one of the more interesting of all astronomical nebulae, the Great Nebula in Orion.

The Kepler 90 Planetary System
28.04.2020

Do other stars have planetary systems like our own? Yes -- one such system is Kepler-90. Cataloged by the Kepler satellite that operated from Earth orbit between 2009 and 2018, eight planets were discovered, giving Kepler-90 the same number of known planets as our Solar System.

APOD: 2024 April 30 Б GK Per: Nova and Planetary Nebula
30.04.2024

The star system GK Per is known to be associated with only two of the three nebulas pictured. At 1500 light years distant, Nova Persei 1901 (GK Persei) was the second closest nova yet recorded. At the very center is a white dwarf star, the surviving core of a former Sun-like star.

Humanity Explores the Solar System
30.04.2013

What spacecraft is humanity currently using to explore our Solar System? Presently, every inner planet has at least one robotic explorer, while several others are monitoring our Sun, some are mapping Earth's Moon, a few are chasing asteroids and comets, one is orbiting Saturn, and several are even heading out into deep space.

HR 8799: Discovery of a Multi planet Star System
17.11.2008

How common are planetary systems like our own Solar System? In the twelve years previous to 2008, over 300 candidate planetary systems have been found orbiting nearby stars. None, however, were directly imaged, few showed evidence for multiple planets, and many had a Jupiter-sized planet orbiting inside the orbit of Mercury.