Children wear protective glasses as they watch for a partial solar eclipse from Sydney's Observatory Hill on April 29, 2014. Australians could see an eclipse with up to two-thirds of the sun obscured by the moon. An annular solar eclipse, also known as a "Ring of Fire," was visible from a small region of Antarctica.
SpaceX's commercial Dragon cargo capsule is grappled by the International Space Station's robotic arm on April 20. The unmanned spacecraft brought nearly two and a half tons of supplies and scientific payloads to the station.
Stars streak above the European Space Agency's Optical Ground Station at the La Teide Observatory on Tenerife in the Canary Islands, in a wide-angle, long-exposure image released on April 27.
The moon glows red over Montevideo, Uruguay, during a total lunar eclipse on April 15. People in most of North and South America were able to witness this year's first total lunar eclipse, which kicked off a rare tetrad of four eclipses over the next two years.
NASA astronaut Steve Swanson works outside the International Space Station on April 23 during a spacewalk to replace a failed backup computer relay box. He was accompanied on the spacewalk by fellow American Rick Mastracchio, who can be seen as a tiny figure refliected in Swanson's helmet visor.
NASA astronaut Rick Mastracchio snaps a "selfie" on April 23 during a repair mission outside the International Space Station. Mastracchio and fellow American Steve Swanson stepped out on a brief spacewalk to install a backup computer after one failed about two weeks earlier.
A bright spot appears on the Martian landscape in this image taken by the Curiosity rover's right-eye camera on April 3. The bright spots attracted a lot of attention from the UFO crowd, but scientists said it was probably a well-placed flash of reflected sunlight.
•Martian Flash Explained, and It's Not What You Think
President Barack Obama listens to a pre-recorded message from the International Space Station as he attends a a youth science event at the National Museum of Emerging Science and Innovation, known as the Miraikan, in Tokyo on April 24. In the background is the "Geo-Cosmos," a globe covered with LED panels that display current satellite imagery of Earth.
A distant group of hot, young stars causes a cloud of hydrogen gas to glow a rosy red 7,300 light-years from Earth, in a view released April 14 by the European Southern Observatory. The cloud, known as Gum 41, lies in the constellation Centaurus. Radiation emitted by the newborn stars near the middle of the image gives the hydrogen a rosy glow in the image from the MPG/ESO 2.2-meter telescope in Chile.
Onlookers watch the launch of a rocket modeled after the Eiffel Tower in St. Petersburg, Russia, on April 13, during celebrations of the 53rd anniversary of the world's first manned spaceflight. Soviet cosmonaut Yuri Gagarin's Vostok spacecraft completed an orbit of the Earth in 1961.
An image captured by NASA's Hubble Space Telescope and unveiled on April 4 shows the largest-known galaxy cluster in the distant universe, cataloged as ACT-CL J0102-4915 and nicknamed "El Gordo" (Spanish for "the fat one.") By measuring how much the cluster's gravity warps images of galaxies in the background, astronomers calculated its mass to be as much as 3 quadrillion times the mass of our sun. Hubble's readings showed that the galaxy cluster, 9.7 billion light-years away from Earth, is roughly 43 percent more massive than previously thought.
Journalists dressed in special suits admire a flying saucer-shaped test vehicle inside the clean room at NASA's Jet Propulsion Laboratory in Pasadena, Calif., on April 9. The agency's Low Density Supersonic Decelerator is designed to allow large payloads to be landed safely on the surface of Mars or other planetary bodies with atmospheres, including Earth.
•NASA Tests Supersonic Flying Saucer
This image from ESO's La Silla Observatory in Chile shows a contrasting pair of galaxies: NGC 1316 and its smaller companion NGC 1317 (right). Although NGC 1317 seems to have had a peaceful existence, its larger neighbor bears the scars of earlier mergers with other galaxies. The image from the MPG/ESO 2.2-meter telescope was released on April 2.
A medium-lift VS07 Soyuz rocket lifts off from its launch pad in Kourou, French Guiana, on April 3. The Russian booster successfully launched Sentinel-1A, the first in a series of European Space Agency satellites that will form the nucleus of Europe's new Copernicus monitoring system. Copernicus is designed to provide better and quicker information about natural disasters and other planetary phenomena.
• See last month's space slideshow