Astronomy Picture Of the Day (APOD)Henize 3 401: An Elongated Planetary Nebula
How do dying stars eject their outer layers? Stars that create elegant planetary nebulas like Henize 3-401, pictured above, are not unusual, causing speculation that, one day, our own Sun may look like this.
A Star Cluster in Motion
Star clusters are a swarm of complex motions. The stars that compose globular clusters and many open clusters all orbit the cluster center, occasionally interacting, gravitationally, with a close-passing star. The orbits of stars around the cluster are typically not as circular as the orbits of planets in our solar system.
A Setting Sun Trail
The Sun appears to move on the sky because the Earth rotates. The extreme brightness of the Sun, however, makes it difficult to capture a sun-trail -- the path the Sun traces on the sky.
An Anomalous SETI Signal
No one knows for sure what caused this signal. There is a slight possibility that it just might originate from an extraterrestrial intelligence. The bright colors on the blue background indicate that an anomalous signal was received here on Earth by a radio telescope involved in a Search for Extraterrestrial Intelligence (SETI).
Apollo 11: Catching Some Sun
Bright sunlight glints and long dark shadows dramatize this image of the lunar surface taken by Apollo 11 astronaut Neil Armstrong, the first to walk on the Moon. Pictured is the mission's lunar...
Clear evening skies are a welcome sight for stargazers worldwide, but clearing skies are good too. Just such a glorious occasion was recorded in this dramatic photo taken by Dominic Cantin during a recent gathering of Canadian astronomers at St-NИrИe Observatory, located about 60 kilometers southeast of the city of Quebec.
NGC 1569: Heavy Elements from a Small Galaxy
For astronomers, elements other than hydrogen and helium are sometimes considered to be simply "heavy elements". It's understandable really, because even lumped all together heavy elements make up an exceedingly small fraction of the Universe. Still, heavy elements can profoundly influence galaxy and star formation ... not to mention the formation of planets and people.
Our Busy Solar System
Our Solar System is a busy place. Although the major planets get the most press, a swarm of rocks, comets, and asteroids also exist. The above plot shows the placement of known inner Solar System objects on 2002 July 20. The light blue lines indicate the orbits of planets.
The View from Everest
What would it be like to stand atop the tallest mountain on Earth? To see a full panoramic vista from there, scroll right. Visible are snow peaked mountains near and far, tremendous cliffs, distant plateaus, the tops of clouds, and a dark blue sky. Mt.
Open Cluster NGC 6520 from CFHT
Did you ever have a day when it felt like a dark cloud was following you around? For the open cluster of stars NGC 6520, every day is like this. On the left of the above picture are many of NGC 6520's bright blue stars.