Planetary Studies
Citizen Scientists Discover Dozens of New Cosmic Neighbors in NASA Data

Using a NASA-designed software program, members of the public helped identify a cache of brown dwarfs – sometimes called failed stars – lurking in our cosmic neighborhood.
We’ve never met some of the Sun’s closest neighbors until now. In a new study, astronomers report the discovery of 95 objects known as brown dwarfs, many within a few dozen light-years of the Sun. They’re well outside the solar system, so don’t experience heat from the Sun, but still inhabit a region astronomers consider our cosmic neighborhood. This collection represents some of the coldest known examples of these objects, which are between the sizes of planets and stars.
Members of the public helped make these discoveries through Backyard Worlds: Planet 9, a NASA-funded citizen science project that is a collaboration between volunteers and professional scientists. Backyard Worlds incorporates data from NASA’s Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE) satellite along with all-sky observations collected between 2010 and 2011 under its previous moniker,WISE. Data from NASA’s retired Spitzer Space Telescope and the facilities of the National Science Foundation’s NOIRLab were also instrumental in the analysis.
Mar’s Solar Conjuction — What Is It & What It Means
Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
andrew.c.good@jpl.nasa.gov
Alana Johnson
NASA Headquarters, Washington
alana.r.johnson@nasa.gov
The daily chatter between antennas here on Earth and those on NASA spacecraft at Mars is about to get much quieter for a few weeks.
That’s because Mars and Earth will be on opposite sides of the Sun, a period known as Mars solar conjunction. The Sun expels hot, ionized gas from its corona, which extends far into space. During solar conjunction, this gas can interfere with radio signals when engineers try to communicate with spacecraft at Mars, corrupting commands and resulting in unexpected behavior from our deep space explorers.
NASA’s Opportunity Rover Mission on Mars Comes to End
DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
Dwayne Brown / JoAnna Wendel
NASA Headquarters, Washington
One of the most successful and enduring feats of interplanetary exploration, NASA’s Opportunity rover mission is at an end after almost 15 years exploring the surface of Mars and helping lay the groundwork for NASA’s return to the Red Planet.
The Opportunity rover stopped communicating with Earth when a severe Mars-wide dust storm blanketed its location in June 2018. After more than a thousand commands to restore contact, engineers in the Space Flight Operations Facility at NASA’s Jet Propulsion Laboratory (JPL) made their last attempt to revive Opportunity Tuesday, to no avail. The solar-powered rover’s final communication was received June 10.
NASA’s Cassini Data Show Saturn’s Rings Relatively New
Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif.
JoAnna Wendel
NASA Headquarters, Washington DC
The rings of Saturn may be iconic, but there was a time when the majestic gas giant existed without its distinctive halo. In fact, the rings may have formed much later than the planet itself, according to a new analysis of gravity science data from NASA’s Cassini spacecraft.
The findings indicate that Saturn’s rings formed between 10 million and 100 million years ago. From our planet’s perspective, that means Saturn’s rings may have formed during the age of dinosaurs.
The conclusions of the research – gleaned from measurements collected during the final, ultra-close orbits Cassini performed in 2017 as the spacecraft neared the end of its mission – are the best answer yet to a longstanding question in solar system science. The findings were published online Jan. 17 in Science.
Scientists Finally Know What Time It Is on Saturn
Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif.
JoAnna Wendel
NASA Headquarters, Washington DC
Using new data from NASA’s Cassini spacecraft, researchers believe they have solved a longstanding mystery of solar system science: the length of a day on Saturn. It’s 10 hours, 33 minutes and 38 seconds.
The figure has eluded planetary scientists for decades, because the gas giant has no solid surface with landmarks to track as it rotates, and it has an unusual magnetic field that hides the planet’s rotation rate.
The answer, it turned out, was hidden in the rings.
NASA’s InSight Places First Instrument on Mars
Jia-Rui Cook / Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
NASA’s InSight lander has deployed its first instrument onto the surface of Mars, completing a major mission milestone. New images from the lander show the seismometer on the ground, its copper-colored covering faintly illuminated in the Martian dusk. It looks as if all is calm and all is bright for InSight, heading into the end of the year.
The Mars InSight Landing Site Is Just Plain Perfect
No doubt about it, NASA explores some of the most awe-inspiring locations in our solar system and beyond. Once seen, who can forget the majesty of astronaut Jim Irwin standing before the stark beauty of the Moon’s Hadley Apennine mountain range, of the Hubble Space Telescope’s gorgeous “Pillars of Creation” or Cassini’s magnificent mosaic of Saturn?
Mars also plays a part in this visually compelling equation, with the high-definition imagery from the Curiosity rover of the ridges and rounded buttes at the base of Mount Sharp bringing to mind the majesty of the American Southwest. That said, Elysium Planitia – the site chosen for the Nov. 26 landing of NASA’s InSight mission to Mars – will more than likely never be mentioned with those above because it is, well, plain.
What Uranus Cloud Tops Have in Common With Rotten Eggs
Even after decades of observations and a visit by NASA’s Voyager 2 spacecraft, Uranus held on to one critical secret — the composition of its clouds. Now, one of the key components of the planet’s clouds has finally been verified.
A global research team that includes Glenn Orton of NASA’s Jet Propulsion Laboratory in Pasadena, California, has spectroscopically dissected the infrared light from Uranus captured by the 26.25-foot (8-meter) Gemini North telescope on Hawaii’s Mauna Kea. They found hydrogen sulfide, the odiferous gas that most people avoid, in Uranus’ cloud tops. The long-sought evidence was published in the April 23rd issue of the journal Nature Astronomy.
The detection of hydrogen sulfide high in Uranus’ cloud deck (and presumably Neptune’s) is a striking difference from the gas giant planets located closer to the Sun — Jupiter and Saturn — where ammonia is observed above the clouds, but no hydrogen sulfide. These differences in atmospheric composition shed light on questions about the planets’ formation and history.
NASA Engineers Dream Big With Small Spacecraft
Many of NASA’s most iconic spacecraft towered over the engineers who built them: think Voyagers 1 and 2, Cassini or Galileo — all large machines that could measure up to a school bus.
But in the past two decades, mini-satellites called CubeSats have made space accessible to a new generation. These briefcase-sized boxes are more focused in their abilities and have a fraction of the mass — and cost — of some past titans of space.
In May, engineers will be watching closely as NASA launches its first pair of CubeSats designed for deep space. The twin spacecraft are called Mars Cube One, or MarCO, and were built at NASA’s Jet Propulsion Laboratory in Pasadena, California.
NASA’s Juno Spacecraft Set for Fifth Jupiter Flyby
DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
Dwayne Brown / Laurie Cantillo
NASA Headquarters, Washington
NASA’s Juno spacecraft will make its fifth flyby over Jupiter’s mysterious cloud tops on Monday, March 27, at 1:52 a.m. PDT (4:52 a.m. EDT, 8:52 UTC).
At the time of closest approach (called perijove), Juno will be about 2,700 miles (4,400 kilometers) above the planet’s cloud tops, traveling at a speed of about 129,000 miles per hour (57.8 kilometers per second) relative to the gas-giant planet. All of Juno’s eight science instruments will be on and collecting data during the flyby.