Scientists have determined that comets produce X-ray emission when particles in the solar wind strike the comet’s atmosphere. Recently, astronomers announced the results of a study using data collected with NASA’s Chandra X-ray Observatory of two comets — C/2012 S1 ISON and C/2011 S4 PanSTARRS — when both were relatively close to Earth.
The elegant simplicity of NGC 4111, seen here in this image from the NASA/ESA Hubble Space Telescope, hides a more violent history than you might think. NGC 4111 is a lenticular, or lens-shaped, galaxy, lying about 50 million light-years from us in the constellation of Canes Venatici (The Hunting Dogs).
Scientists on NASA’s New Horizons mission team are learning more about the structure and behaviour of Pluto’s complex atmosphere by discovering new attributes of its extensive haze layers. The hazes were first discovered by New Horizons in July 2015, as the spacecraft swept past Pluto and made its historic first exploration of the mysterious dwarf planet.
As dusk fades to dark on Sunday, 17 April, observers in the British Isles should look up to the southern sky to see the 10-day-old waxing gibbous Moon and Jupiter just four degrees apart, within the same binocular field of view. Jupiter’s largest moon, Ganymede, and second Galilean moon, Europa, provide some events for telescope owners to view at higher magnifications.
Vixen has introduced a remarkable looking 7-element ocular that yields an expansive 83° apparent field. Yet the optical somersaults entailed in doing so are achieved without harm to the final image, yielding a stellar field with sharp edge-to-edge field definition with no vignetting – even on instruments of low focal ratio, says reviewer Steve Ringwood.
NASA’s Kepler planet-hunter spacecraft remains stable as the process of returning it to science continues. The cause of the anomaly, first reported on 8 April, remains under investigation. Charlie Sobeck, Kepler and K2 mission manager at NASA’s Ames Research Center, explains the steps taken by mission operations engineers to resume the K2 mission.
As it orbits Jupiter, the icy surface of Europa heaves and falls with the changing pull of its parent planet’s gravity, creating enough heat to likely support a global ocean beneath the Jovian moon’s solid shell. Experiments by geoscientists suggest that this process, called tidal dissipation, could create far more heat in Europa’s ice than scientists had previously assumed.
NASA’s Cassini spacecraft has been in orbit around Saturn since 2004, studying the giant planet, its rings and its moons. Among the myriad microscopic grains collected by Cassini, a special three dozen stand out from the crowd. Scientists conclude these specks of material came from interstellar space — the space between the stars.
The “Spider Nebula” glows fluorescent green in an infrared image from NASA’s Spitzer Space Telescope and the Two Micron All Sky Survey (2MASS). Nebulae are clouds of interstellar gas and dust where stars can form. The Spider, officially named IC 417, is located about 10,000 light-years from Earth in the constellation Auriga.
Subtle distortions hidden in a stunning Atacama Large Millimetre/submillimetre Array (ALMA) image of the gravitational lens SDP.81 are telltale signs that a dwarf dark galaxy is lurking in the halo of a much larger galaxy nearly 4 billion light-years away. This discovery could help astronomers address important questions on the nature of dark matter.