Are we missing a member of our solar system? Credit: Jet Propulsion Laboratory

Evidence may be mounting that either a brown dwarf star or a gas giant planet exists at the far reaches of the solar system — way beyond even Pluto. Named Tyche, it could be four times the size of our largest know planet, Jupiter, and 15,000 times farther from Sun than Earth.

• CNN on the hunt for another planet in our solar system.
• Space.com on the Tyche debate.
• The Jet Propulsion Laboratory on the search.

An artist's illustration of Kepler candidates and their home star. Credit: NASA/Tim Pyle

NASA’s Kepler mission is designed to discover planets. It looks for the dimming in a star that occurs as a passing planet blocks a tiny fraction of its star’s light. The Kepler team has released new results that suggest that at least one system it examined contains several planets in the habitable zone, the area where water might exist. Water is a necessity for an environment that can sustain life as we know it.

• Kepler's planet candidates.

Bursts of hot gas on the Sun. Credit: NASA Goddard/SDO/AIA

Why the Sun’s corona, or outer layer, is millions of degrees hotter than its surface is a long-standing mystery. A new discovery reveals a major source of hot gas that replenishes the corona — jets of super-hot plasma that shoot up from just above the Sun’s surface.

• Scientific American on the plasma jets.
• NASA news release on the discovery.

The Sagittarius Dwarf Galaxy is one of the small galaxies neighboring the Milky Way.

You’ve heard of Planet X — the idea, popular with science fiction enthusiasts and conspiracy addicts, that there might be an undetected planet out there in our solar system. But how about Galaxy X?

Astronomers using numerical models predict the presence of a dwarf galaxy 600,000 light years from the center of the Milky Way. The galaxy may be too faint to see in visible light – but observers with infrared and radio telescopes could find it.

• University of California, Berkeley news release on the investigation.
• Space.com on the discovery.

An annotated look at the Milky Way galaxy.

There’s a pattern of forms of life on Earth growing both more and less diverse over time, and we may be able to trace it back to our solar system’s path through the Milky Way galaxy. Every 60 million years or so, our solar system emerges north out of the average plane of the galaxy’s disk, and the variety of Earthly life drops. It may be due to increased exposure to high-energy cosmic rays.

• Live Science on the discovery.
• Astrodigital on the location of our solar system in the Milky Way.

Artist's depiction of an extrasolar planet near its sun.

Many extrasolar planets have been found using the transit technique. This occurs when a planet blocks some of the light from its parent star as it orbits in front of it. If astronomers detect a repeating pattern, they can glean information about the planet’s orbit. Most of these planets are very close to their host stars, and so they are very hot. A new record has been set in the WASP-33 system. The planet, called WASP-33b, appears to be 3200 degrees Celsius, or about 5800 Fahrenheit!

• Science Shot on the new record breaker.
• Extrasolar Planets Encyclopedia information on WASP-33b.

An artist's illustration of a balloon exploring Titan. Credit: JPL

The next mission to Titan could provide a true bird’s-eye view of Saturn’s moon. Scientists might send a balloon or a blimp cruising through its skies for months. NASA’s Cassini spacecraft has been flying past Titan for several years, and the Huygens probe landed and sent back data during a 2005 descent to the surface, but many questions remain that could benefit from a long-term mission.

• Space.com on a potential moon blimp mission.
• The Jet Propulsion Laboratory discusses a moon blimp mission.
• The Cassini Mission.

Hubble has located the faintest galaxy yet seen, a dim collection of blue stars that existed just 480 million years after the Big Bang. And astronomers find that tiny red dwarf stars can unleash mighty eruptions, making life difficult for any planets orbiting nearby.

• NASA's Hubble Finds that Puny Stars Pack a Big Punch
• NASA's Hubble Finds Most Distant Galaxy Candidate Ever Seen in Universe