Best Space Stories of the Week – July 26, 2015

Earth's 'Cousin' Exoplanet, Kepler-452b
The artist's illustration compares Earth (left) to the newly discovered planet, Kepler-452b, which measures about 60 percent larger. Image released July 23, 2015. (Image credit: NASA/Ames/JPL-Caltech/T. Pyle)

Planet like an older Earth is found, Stephen Hawking signs on to an ambitious search for extraterrestrial life and a faulty strut is proposed as the cause of SpaceX's rocket explosion in's top news stories of the week.

Earth's older cousin spotted

Scientists have taken one step closer to finding Earth's twin in space: New data from the Kepler Space Telescope reveal a likely rocky world orbiting a sun-like star among 500 new planets spotted. Kepler-452b is larger than Earth and its star is older, but the year is almost equivalent to Earth's and its sun would look quite familiar in the sky. [Full Story: NASA Finds Closest Earth Twin Yet in Haul of 500 Alien Planets]

Living on Kepler-452b, the newest Earth-like planet

Any human visitors to the newly-discovered Kepler-452b would feel the weight of almost twice Earth's gravity, but they could adapt, and Earth's plants could photosynthesize its sunlight just fine — more concerning would be the future runaway greenhouse effect, like that on Venus. [Full Story: Kepler-452b: What It Would Be Like to Live On Earth's 'Cousin']

New crew heads to Space Station

After a delay of two months, a Russian Soyuz rocket has successfully launched three new crew members to the International Space Station, including one NASA astronaut. They join the current crew of three who have been alone on the station since June 11. [Full Story: Russia Launches New Space Station Crew After 2-Month Delay]

Ultra-ambitious project hunts for alien intelligence

Two new initiatives, funded by investor Yuri Milner, will scan the stars for signs of E.T., in the most powerful search in history, and compose messages to potentially send out to alien civilizations. Stephen Hawking described the $100 million, 10-year search, called Breakthrough Listen, at the Royal Society July 20.  [Full Story: Stephen Hawking Helps Launch Massive Search for E.T.]

Stephen Hawking seeks intelligent life despite catastrophic consequences

Although Hawking is known to fear humanity's destruction upon encountering advanced alien species, he's still lent his support to the new Breakthrough Listen initiative hunting for them. [Full Story: Stephen Hawking: Intelligent Aliens Could Destroy Humanity, But Let's Search Anyway]

NASA project scientist Claudia Alexander dies at 56

Claudia Alexander, a planetary scientist who spearheaded NASA's side of the European Rosetta comet mission and the Galileo mission to Jupiter, has died after a 10-year battle with breast cancer. Alexander was also known as a science communicator, mentor, and science fiction author. [Full Story: Claudia Alexander, Beloved NASA Project Scientist, Dies at 56]

Faulty strut most likely cause of Falcon 9 rocket explosion

SpaceX CEO and founder Elon Musk announced that the space station resupply mission's failure in June was likely caused by a faulty strut within the booster's upper stage, intended to support bottles storing frozen helium. SpaceX plans to change suppliers for the struts and individually test each of the 200 struts onboard every rocket. [Full Story: SpaceX Rocket Explosion Likely Caused by Faulty Strut, Elon Musk Says]

SpaceX explosion jolt awake for CEO

Elon Musk told reporters that the strut failure and subsequent rocket explosion re-introduce a sense of caution to the quickly-expanding company. [Full Story: SpaceX 'Complacent' Before Rocket Explosion, Elon Musk Says]

Pulsar rams stellar disk, sending debris racing away

An ultra-dense neutron star's orbit brought it through the disk of dust surrounding its neighboring star, sending a giant cloud of dust the width of 100 solar systems flying. The debris eventually reached 15 percent the speed of light just as the Chandra X-ray Observatory caught it on camera. [Full Story: Powerful Pulsar Knocks Star's Block Off]

Dark matter lurks in dead galaxy cluster

47 galaxies in the Coma Cluster hold far fewer stars than the Milky Way, but still stick together; that extra gravitational kick might come from almost 100 times more dark matter than visible, new research suggests. [Full Story: Galaxy Graveyard May Be Overflowing with Dark Matter]

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Sarah Lewin
Associate Editor

Sarah Lewin started writing for in June of 2015 as a Staff Writer and became Associate Editor in 2019 . Her work has been featured by Scientific American, IEEE Spectrum, Quanta Magazine, Wired, The Scientist, Science Friday and WGBH's Inside NOVA. Sarah has an MA from NYU's Science, Health and Environmental Reporting Program and an AB in mathematics from Brown University. When not writing, reading or thinking about space, Sarah enjoys musical theatre and mathematical papercraft. She is currently Assistant News Editor at Scientific American. You can follow her on Twitter @SarahExplains.