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As Shenzhou 10 returns to Earth, China calls for international cooperation in manning space

The Chinese space program successfully performed a 15-day mission in Earth-orbit, their longest manned space mission so far, marking a significant milestone in China’s journey into the final frontier. On June 26, the Shenzhou 10 capsule safely returned the three astronauts to Earth.

From its start, the mission was graced with reverence and momentous occasions. Chinese President Xi Jinping attended the launch ceremony on June 11 at the Jiuquan Satellite Launch Center in Gansu Province in northwestern China. As reported by Chinese news agency Xinhua, President Xi said that the mission would “represent the lofty aspirations of the Chinese people to explore space.”

President Xi also spoke with the astronauts via video call on June 24, affirming that their mission is “part of the dream to make China stronger.” In another special event, female astronaut Wang Yaping gave a 50-minute science lecture from orbit, to the delight of 60 million Chinese students. Wang demonstrated, among other things, the effects of a zero-gravity environment on the surface tension of water and answered questions on topics as varied as the recycling of water in space, orbital debris, and the effects of zero-gravity on the human body.

The Shenzhou 10 capsule rode a Long March-2F rocket into orbit on June 11 and three days later docked with the uncrewed Tiangong-1 space station, which has been in orbit since 2011. This first docking maneuver was accomplished automatically.

On June 23, the Shenzhou 10 crew performed a manual separation from Tiangong-1. Later that day, astronaut Nie Haisheng manually piloted Shenzhou 10 back to Tiangong-1 and docked with the station. Wang Yaping and fellow astronaut Zhang Xiaoguang provided support by monitoring the capsule’s instruments.

The purpose of Shenzhou 10’s mission was to assess docking technology and astronaut support systems, and continue to lay the foundation for the next phase of China’s space program. Tiangong-1 is merely a prototype module and will not receive additional visitors. The Tiangong-2 and Tiangong-3 modules will launch in 2015 and further China’s ambition of launching and assembling the components of a permanent space station in the early 2020s. China is currently building Long March-5 rockets capable of ferrying 20 tons of cargo into Earth-orbit to build and maintain the eventual space station.

Even with such notable achievements as Shenzhou 10’s recent mission, the director of China’s manned space program, Wang Zhaoyao, admitted that “there is still a very large gap between China and the leading space countries in terms of manned space technology and capability.”

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NASA spots another massive near-Earth asteroid

The planets and moons of our solar system might receive the most fanfare and, in some cases, visits by small fleets of probes and landers, but they are far outnumbered by asteroids and comets. The Pan-STARRS-1 telescope in Hawaii has attained a major milestone: the 10,000th near-Earth object (NEO), an asteroid known as 2013 MZ5 that was detected on June 18. NEOs are those comets and asteroids that approach Earth’s orbital distance to within approximately 28 million miles (45 million kilometers).

Asteroid 2013 MZ5’s orbit will not bring it close enough to Earth to pose a threat. At approximately 1,000 feet (300 meters) across, asteroid 2013 MZ5 is far from matching the largest NEOs in size. The biggest near-Earth asteroid, discovered in 1924 by German astronomer Walter Baade, is a 25-mile-wide (41 kilometers) behemoth known as 1036 Ganymed.

The first NEO was recognized in 1898, and around 500 were discovered during the following century. However, the rate of NEO discovery now stands at approximately 1,000 per year, an average of three per day, thanks to NASA’s Near-Earth Object Observations Program. This program, which began in 1998, is a collaborative effort that includes the Massachusetts Institute of Technology Lincoln Laboratory Near-Earth Asteroid Research (LINEAR), Jet Propulsion Laboratory Near-Earth Asteroid Tracking (NEAT), University of Arizona (Spacewatch, later Catalina Sky Survey), Lowell Observatory Near-Earth Object Search (LONEOS), University of Hawaii’s aforementioned Pan-STARRS-1 telescope, Japanese Spaceguard Association (JSGA), and the Asiago DLR Asteroid Survey (ADAS) in Italy.

The discoveries made by these research teams are reported to the Minor Planet Center at the Smithsonian Astrophysical Observatory in Cambridge, MA. LINEAR, Catalina Sky Survey, and Pan-STARRS are currently the most productive participants.

Within 12 years of its commencement, the NEO Observations Program had discovered 90% of NEOs more than 3,300 feet (one kilometer) wide, and the program now strives to achieve the same goal with NEOs wider than 500 feet (140 kilometers). Upon attainment of this goal, only a 1% risk will exist that an NEO will strike Earth without warning; NEOs that we see coming can be deflected with today’s technology.

Approximately 30% of 460-foot-wide NEOs have been catalogued, but less than 1% of 100-foot-wide NEOs have been detected. NEOs that are approximately 100 feet (30 meters) wide have been estimated to number over one million, and are the smallest objects that pose a devastating danger to populated areas if they impact on Earth.

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Gliese 667 may hold three planets capable of supporting life

New observations of the star system Gliese 667 have led to the discovery of three planets inside a star’s habitable zone, the region in which liquid water might exist. Gliese 667 is a trinary system that includes three stars, Gliese 667A, 667B, and 667C, and is situated 22 light-years from Earth in the constellation Scorpius.

With three stars, the Gliese 667 system is quite different from our own solar system, and yet there is now a crucial similarity: three planets in a habitable zone. In our solar system, Earth is of course located squarely in our Sun’s habitable zone, with Venus scraping the inner edge of the zone and Mars the outer edge. In the Gliese 667 system, three planets are now known to orbit Gliese 667C inside the star’s habitable zone.

Previous studies had identified three planets orbiting Gliese 667C, with one in the habitable zone. The new study, led by Guillem Anglada-Escudé of the University of Göttingen, Germany and Mikko Tuomi of the University of Hertfordshire, UK, has determined that Gliese 667C actually hosts seven planets: two hotter worlds orbiting too close to the star to be in the habitable zone, the three planets in the habitable zone, and two more frigid planets orbiting farther from the star.

The two hot worlds and the three habitable-zone planets are likely tidally locked, meaning that one side of the planet always faces its star and the other side faces away and is perpetually shrouded in darkness. The three habitable-zone planets are all super-Earths, more massive than Earth but less massive than Uranus or Neptune.

Because Gliese 667C is only approximately one-third as massive as our Sun, its planets’ orbits are far smaller than those in our solar system and its habitable zone is closer, within an orbit the size of Mercury’s around our Sun.

The three habitable-zone worlds orbiting Gliese 667C mark two major milestones in the search for exoplanets. This is the first discovery, outside of our solar system, of three planets orbiting in the habitable zone of a single star. It is also the first time a relatively low-mass star, such as Gliese 667C, has been determined to host several planets in its habitable zone.

The discovery of the additional planets orbiting Gliese 667C was due to data gathered by numerous telescopes, including the European Southern Observatory’s (ESO) Very Large Telescope in Chile, Magellan II Telescope at the Las Campanas Observatory in Chile, High Accuracy Radial velocity Planet Searcher at ESO’s 3.6-meter telescope in Chile, and the Keck telescope on Mauna Kea in Hawaii.

The discovery is described in the journal Astronomy & Astrophysics.

More information can be found here.