John Grunsfeld – Page 2

NASA's reworked image of Europa based on late 1990s data from the Galileo spacecraft.

Science instruments selected for NASA’s Europa mission

27 May 2015 Astronomy Now

NASA has selected nine science instruments for a future mission to Jupiter’s moon Europa in which a spacecraft would make multiple close flybys of the icy world — thought to contain a global subsurface ocean — to investigate whether the mysterious moon could harbour conditions suitable for life.

New Horizons detects features and possible polar cap on Pluto

30 April 2015 Astronomy Now

For the first time, images from NASA’s New Horizons spacecraft are revealing bright and dark regions on the surface of faraway Pluto — the primary target of the New Horizons close flyby in mid-July.

Celestial fireworks celebrate Hubble’s silver anniversary

24 April 2015 Astronomy Now

A brilliant tapestry of young stars flaring to life resemble a glittering fireworks display in the Hubble Space Telescope image chosen to commemorate the orbiting observatory’s quarter century of exploring the Solar System and beyond.

Hubble views of Ganymede’s aurorae suggest a vast salty subsurface ocean

13 March 2015 Astronomy Now

Jupiter’s moon Ganymede is the largest moon in our Solar System and the only moon with its own magnetic field. NASA’s Hubble Space Telescope has the best evidence yet for a 60-mile deep underground saline ocean on Ganymede, believed to contain more water than all the water on Earth’s surface.

Hydrothermal activity in subsurface ocean of Saturn’s moon Enceladus

12 March 2015 Astronomy Now

NASA’s Cassini spacecraft finds the first evidence of active hot-water chemistry beyond planet Earth on Saturn’s ocean moon Enceladus — results that have important implications for the habitability of icy worlds.