The Observable Universe
8.05.2018

How far can you see? Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you -- is the observable universe. In visible...

APOD: 2025 November 23 Б The Observable Universe
23.11.2025

How far can you see? Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you -- is the observable universe. In light...

The Observable Universe
16.03.2022

How far can you see? Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you -- is the observable universe. In light...

HD 188753: Triple Sunset
5.08.2005

Although it looks like fiction, this artist's vision of sunset on an alien world is based on fact -- the recent discovery of a hot, jupiter-sized planet orbiting in triple star system HD 188753.

Pioneer 10: The First 6 Billion Miles
3.03.1997

Q: What was made by humans and is 6 billion miles away? A: Pioneer 10 - and yesterday was the 25th anniversary of its launch. More than 9 light hours distant, Pioneer 10 is presently about twice as far from the Sun as Pluto, bound for interstellar space at 28,000 miles per hour.

APOD: 2026 September 18 Б Messier 33: The Triangulum Galaxy
18.09.2026

The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, Messier 33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way.

APOD: 2023 October 4 Б IC 2118: The Witch Head Nebula
4.10.2023

Does this nebula look like the head of a witch? The nebula is known popularly as the Witch Head Nebula because, it is said, the nebula's shape resembles a Halloween-style caricature of a witch's head. Exactly how, though, can be a topic of imaginative speculation.

Twistin By The Lagoon
25.09.1999

The awesome spectacle of starbirth produces extreme stellar winds and intense energetic starlight -- bombarding dusty molecular clouds inside the Lagoon Nebula (M8). At least two long funnel shaped clouds, each roughly half a light-year long, have apparently been formed by this activity.

Star Trails for a Red Planet
30.11.2019

Does Mars have a north star? In long exposures of Earth's night sky, star trails make concentric arcs around the north celestial pole, the direction of our fair planet's axis of rotation. Bright star Polaris is presently the Earth's North Star, close on the sky to Earth's north celestial pole.

NGC 2419 Intergalactic Wanderer
4.06.2015

Three objects stand out in this thoughtful telescopic image, a view toward the mostly stealthy constellation Lynx. The two brightest (the spiky ones) are nearby stars. The third is the remote globular star cluster NGC 2419, at distance of nearly 300,000 light-years.