Written by Elizabeth Landau
Pasadena, CA – The day was officially a bit longer than usual on Tuesday, June 30th, 2015, because an extra second, or “leap” second, was added.
“Earth’s rotation is gradually slowing down a bit, so leap seconds are a way to account for that,” said Daniel MacMillan of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Strictly speaking, a day lasts 86,400 seconds. That is the case, according to the time standard that people use in their daily lives – Coordinated Universal Time, or UTC. UTC is “atomic time” – the duration of one second is based on extremely predictable electromagnetic transitions in atoms of cesium. These transitions are so reliable that the cesium clock is accurate to one second in 1,400,000 years.
Written by Elizabeth Landau / Preston Dyches
Pasadena, CA – Saturn’s moon Titan is home to seas and lakes filled with liquid hydrocarbons, but what forms the depressions on the surface? A new study using data from the joint NASA and the European Space Agency (ESA) Cassini mission suggests the moon’s surface dissolves in a process that’s similar to the creation of sinkholes on Earth.
Apart from Earth, Titan is the only body in the solar system known to possess surface lakes and seas, which have been observed by the Cassini spacecraft. But at Titan’s frigid surface temperatures — roughly minus 292 degrees Fahrenheit (minus 180 degrees Celsius) — liquid methane and ethane, rather than water, dominate Titan’s hydrocarbon equivalent of Earth’s water.
Written by Dwayne Brown / Laurie Cantillo
Washington, D.C. – Beyond Earth, Jupiter’s moon Europa is considered one of the most promising places in the solar system to search for signs of present-day life, and a new NASA mission to explore this potential is moving forward from concept review to development.
NASA’s mission concept — to conduct a detailed survey of Europa and investigate its habitability — has successfully completed its first major review by the agency and now is entering the development phase known as formulation.
Written by Preston Dyches / DC Agle
Pasadena, CA – NASA’s Cassini spacecraft made a close flyby of Saturn’s moon Dione on June 16th, coming within 321 miles (516 kilometers) of the moon’s surface. The spacecraft made its closest approach to Dione at 1:12pm PDT (4:12pm EDT) on June 16th.
During the flyby, Cassini’s cameras and spectrometers observed terrain that includes “Eurotas Chasmata,” a region first observed 35 years ago by NASA’s Voyager mission as bright, wispy streaks. After the Voyager encounter, scientists considered the possibility that the streaks were bright material extruded onto the surface by geologic activity, such as ice volcanoes.
Written by Dr. Tony Phillips
Washington, D.C. – If you love stargazing, there’s a date you need to mark on your calendar. It’s June.
That’s right, the whole month!
Throughout the month of June 2015, the two brightest planets in the night sky, Venus and Jupiter, are going to converge for a jaw-dropping close encounter. You don’t want to miss any of the action.
When the sun goes down, step outside and look west. You don’t have to wait until the sky fades to black. Venus and Jupiter are so bright, you can see then shining through the twilight.
Written by Felicia Chou
Washington, D.C. – If you lived on one of Pluto’s moons, you might have a hard time determining when, or from which direction, the sun will rise each day. Comprehensive analysis of data from NASA’s Hubble Space Telescope shows that two of Pluto’s moons, Nix and Hydra, wobble unpredictably.
“Hubble has provided a new view of Pluto and its moons revealing a cosmic dance with a chaotic rhythm,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate in Washington. “When the New Horizons spacecraft flies through the Pluto system in July we’ll get a chance to see what these moons look like up close and personal.”
NASA’s Alice instrument aboard Rosetta spacecraft makes discovery on Comet 67P/Churyumov-Gerasimenko
Written by DC Agle
Pasadena, CA – Data collected by NASA’s Alice instrument aboard the European Space Agency’s Rosetta spacecraft reveal that electrons close to the surface of comet 67P/Churyumov-Gerasimenko — not photons from the sun, as had been believed — cause the rapid breakup of water and carbon dioxide molecules spewing from the comet’s surface.
“The discovery we’re reporting is quite unexpected,” said Alan Stern, principal investigator for the Alice instrument at the Southwest Research Institute (SwRI) in Boulder, Colorado. “It shows us the value of going to comets to observe them up close, since this discovery simply could not have been made from Earth or Earth orbit with any existing or planned observatory. And, it is fundamentally transforming our knowledge of comets.”
Written by Preston Dyches
Pasadena, CA – NASA’s Cassini spacecraft has returned images from its final close approach to Saturn’s oddball moon Hyperion, upholding the moon’s reputation as one of the most bizarre objects in the solar system. The views show Hyperion’s deeply impact-scarred surface, with many craters displaying dark material on their floors.
During this flyby, Cassini passed Hyperion at a distance of about 21,000 miles (34,000 kilometers) at closest approach. Cassini’s closest-ever Hyperion flyby took place on September 26th, 2005, at a distance of 314 miles (505 kilometers).
Written by Preston Dyches
Pasadena, CA – NASA’s Cassini spacecraft will make its final close approach to Saturn’s large, irregularly shaped moon Hyperion on Sunday, May 31st.
The Saturn-orbiting spacecraft will pass Hyperion at a distance of about 21,000 miles (34,000 kilometers) at approximately 6:36am PDT (9:36am EDT). Mission controllers expect images from the encounter to arrive on Earth within 24 to 48 hours.
Written by Preston Dyches
Pasadena, CA – Two powerful science investigations will help unravel the mystery of whether Jupiter’s icy moon Europa might have the right conditions for life, when a new NASA mission heads there sometime in the 2020s. Led by researchers at NASA’s Jet Propulsion Laboratory in Pasadena, California, the instruments include an infrared imaging spectrometer and a magnetometer.
NASA announced selection of ICEMAG, MISE and seven other investigations for the Europa mission’s science payload on May 26th, 2015. The space agency received 33 proposals for science instruments to fly onboard its planned Europa mission, which would orbit Jupiter and conduct repeated close flybys of the small moon during a three-year period.
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