NASA Succeeded to Alter an Asteroid Trajectory

Two weeks ago, the asteroid Dimorphos was minding its own business, quietly orbiting around its partner Didymos, when suddenly NASA’s DART spacecraft plowed into it at 14,000 miles per hour.

The space agency and its partners planned that collision to see whether such an impact could alter an asteroid or comet’s trajectory—should humanity ever need to defend the planet from an oncoming space rock. Before the crash on September 26, Dimorphos circled its neighbor like clockwork: one lap every 11 hours and 55 minutes. If the DART test was successful, the proof would be a change in that orbital period, showing that the refrigerator-sized spacecraft had nudged the asteroid onto a different path. Now the DART team has an answer: It worked—even better than expected.

For the first time ever, humanity has changed the orbit of a planetary body,” said Lori Glaze, director of the Planetary Science Division at NASA headquarters in Washington, at a press conference today revealing the result.

The team would have considered a 10-minute difference a success, said NASA chief Bill Nelson. But DART actually shortened the asteroid’s orbit by a whopping 32 minutes. Dimorphos now takes only about 11 hours and 23 minutes to circle its partner, he said—a significant change, meaning that it is indeed possible to deflect a small asteroid’s path.


China Has Made Astounding Progress on Hypersonic Weapons

China tested a nuclear-capable hypersonic missile in August that circled the globe before speeding towards its target, demonstrating an advanced space capability that caught US intelligence by surprise. Five people familiar with the test said the Chinese military launched a rocket that carried a hypersonic glide vehicle which flew through low-orbit space before cruising down towards its target.

The missile missed its target by about two-dozen miles, according to three people briefed on the intelligence. But two said the test showed that China had made astounding progress on hypersonic weapons and was far more advanced than US officials realised. The test has raised new questions about why the US often underestimated China’s military modernisation.

We have no idea how they did this,” said a fourth person.

The US, Russia and China are all developing hypersonic weapons, including glide vehicles that are launched into space on a rocket but orbit the earth under their own momentum. They fly at five times the speed of sound, slower than a ballistic missile. But they do not follow the fixed parabolic trajectory of a ballistic missile and are manoeuvrable, making them harder to track.

Taylor Fravel, an expert on Chinese nuclear weapons policy who was unaware of the test, said a hypersonic glide vehicle armed with a nuclear warhead could help China “negateUS missile defence systems which are designed to destroy incoming ballistic missiles. “Hypersonic glide vehicles . . . fly at lower trajectories and can manoeuvre in flight, which makes them hard to track and destroy,” said Fravel, a professor at the Massachusetts Institute of Technology.

Water Found On A Potentially Life-friendly Alien Planet

In a first for astronomers studying worlds beyond our solar system, data from the Hubble Space Telescope have revealed water vapor in the atmosphere of an Earth-size planet. Although this exoplanet orbits a star that is smaller than our sun, it falls within what’s known as the star’s habitable zone, the range of orbital distances where it would be warm enough for liquid water to exist on a planet’s surface. The discovery, announced this week in two independent studies, comes from years of observations of the exoplanet K2-18b, a super-Earth that’s about 111 light-years from our solar system. Discovered in 2015 by NASA’s Kepler spacecraft, K2-18b is very unlike our home world: It’s more than eight times the mass of Earth, which means it’s either an icy giant like Neptune or a rocky world with a thick, hydrogen-rich atmosphere.

K2-18b’s orbit also takes it seven times closer to its star than Earth gets to the sun. But because it circles a type of dim red star known as an M dwarf, that orbit places it in the star’s potentially life-friendly zone. Crude models predict that K2-18b’s effective temperature falls somewhere between -100 and 116 degrees Fahrenheit, and if it is about as reflective as Earth, its equilibrium temperature would be roughly the same as our home planet’s.

This is the only planet right now that we know outside the solar system that has the correct temperature to support water, it has an atmosphere, and it has water in it—making this planet the best candidate for habitability that we know right now,” University College London astronomer Angelos Tsiaras, a coauthor of one of the two studies, said during a press conference.