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SpaceX's triumph, exoplanets and mysterious killer whales: This week in space and science

By Ashley Strickland, CNN | Posted - Mar 10th, 2019 @ 7:31am



CNN — This week saw the beginning of a new era of human spaceflight, thanks to the launch and return of SpaceX's Crew Dragon capsule, the first commercially operated spacecraft designed to carry astronauts. It's not shuttling humans just yet, but it did have some interesting cargo.

Scientists found a mysterious new kind of killer whale, asteroids aren't anything like they were in "Armageddon," and the Milky Way weighs a lot. Exoplanets also had their moment in the sun this week.

And there was the discovery of the tragic site of a mass sacrifice from the 15th century, involving 137 children and more than 200 juvenile llamas that may have had their hearts cut out. You may want to read that another time, when you're not about to have brunch.

Here's everything you missed this week in space and science. And don't forget to move your clocks forward one hour this weekend!

A big win for SpaceX, Ripley and Little Earth

The SpaceX Crew Dragon capsule launched March 2 and completed its historic mission Friday. The capsule docked at the International Space Station to deliver supplies, spent the week attached to the station and then splashed back down on Earth. It's been designed to carry astronauts to the space station as early as June or July, but no humans were on board for this historic test flight.

NASA astronaut Anne McClain tweeted that it was "the dawn of a new era in human spaceflight," along with a photo of the capsule.

Vice President Mike Pence called the astronauts on the station to congratulate them on this achievement and all that it implies for the future.

But Crew Dragon wasn't without its distracting delights. Along for the ride was Ripley, a space-suited dummy named for Ellen Ripley from the "Alien" films.

Ripley was meant to make sure that the spacecraft would be safe and comfortable for humans. Ripley even has little sensors at key points like the head, neck and spine to see what the experience might be like for astronauts who could be using it later this year.

And then there was Little Earth, an adorably wonderful plush toy representing our planet. Little Earth, also called Buddy, has enjoyed an eventful week tagging along with the astronauts. While Crew Dragon has returned to Earth with Ripley on board, Little Earth gets to enjoy an extended vacation until July. That means he'll get to watch McClain and Christina Koch conduct the first all-female spacewalk this month.

Throughout the week, McClain shared delightful photos on Twitter of the plushie accompanying her during tasks, experiments, workouts and even dinner.

And of course, Little Earth got to see Big Earth from the best vantage point. "Yes, buddy, that's your Mother Earth. Isn't she beautiful?" McClain tweeted, accompanied by a picture that's too cute for words.

You can catch the full recap of his big week here. And don't worry, we'll keep reporting back on Little Earth's shenanigans.

Shockwaves are beautiful

The speed of sound (not the Coldplay song) is associated with sonic booms and supersonic jets. But have you ever wondered what it looks like? Hint: You've never seen anything like it.

Courtesy of NASA

It took 10 years to develop the technology that would allow air-to-air photography capturing the interaction of shockwaves from two supersonic planes. The two US Air Force T-38 supersonic jets performed a test flight in California flying 30 feet apart to create interacting shockwaves.

A NASA B-200 King Air aircraft flew 2,000 feet below the planes and captured photos at 1,400 frames per second.

The shockwaves seen in the photo create supersonic booms when they merge in the atmosphere, which breaks the sound barrier. Supersonic flights that don't make this noise but rather more of a low rumble could lift the restrictions on supersonic flight over land. These photos can help researchers test and develop that technology.

"I am ecstatic about how these images turned out," J.T. Heineck, a scientist at NASA's Ames Research Center, said in a statement. "We never dreamt that it would be this clear, this beautiful."

New whale, who dis?

A new type of whale has been spotted, "Type D" to be exact. What does that mean? Well, Type D whales look like killer whales, or orcas, but they have a more rounded head, smaller white markings around the eyes and a different body shape.

Killer whale; NOAA

An international team of scientists spotted them off the coast of Cape Horn in Chile and took small biopsies to study them.

"We are very excited about the genetic analyses to come," Bob Pitman, a researcher from NOAA Fisheries' Southwest Fisheries Science Center, said in a release. "Type D killer whales could be the largest undescribed animal left on the planet and a clear indication of how little we know about life in our oceans."

Asteroid menace

Besides the fact that Hollywood was totally wrong about what it might be like to fly through an asteroid field (thanks, "Star Wars"), the film industry was also wrong about how easy it might be to obliterate an asteroid (thanks, "Armageddon").

A new study simulated a small asteroid, with a diameter spanning just under a mile, colliding with a larger one about 16 miles across. The large asteroid was pretty much unharmed. Gravity could even help pull any disturbed fragments back together.

So it's going to take a lot more power and energy to destroy an asteroid that is, say, heading for Earth.

For the sake of being able to sleep at night, NASA and other space organizations around the world are focused on detecting the threat of near-Earth objects, asteroids and comets whose orbits place them within 30 million miles of Earth.

How much would the Milky Way weigh if the Milky Way could be weighed?

Consider this your free trivia tip: The Milky Way is heavy. But now, scientists have a better idea of how heavy that is.

The Milky Way; CNN

It's not as if the Milky Way, or even stars and planets, can be put on a scale. Using data from NASA's Hubble Space Telescope and the European Space Agency's Gaia satellite, astronomers have determined the most accurate measurement of its mass: Our vast galaxy clocks in at 1.5 trillion solar masses.

One solar mass is the mass of our sun, which is 2 times 10 to the 30th power kilograms.

So where does all of that weight come from? Surprisingly, only a small percentage of this is due to the galaxy's 200 billion stars and the 4 million-solar-mass supermassive black hole at the center. The rest of it is due to dark matter, that elusive substance that holds the universe together.

Astronomers are still trying to find evidence of dark matter to see whether it's a particle or something else. But they know that it's present, even if it can't be detected yet.

And as far as galaxies go, ours is a heavy one compared with others, but it's also appropriate considering how bright it is. Lighter galaxies weigh in at around a billion solar masses. The heaviest are 30 trillion solar masses.

So, it's as heavy as it needs to be.

Hot Jupiters, so hot right now

Congratulations are in order for Kepler-1658 b. It's finally been deemed a planet after being discovered by the Kepler Space Telescope 10 years ago. Kepler's mission revolutionized the search for other worlds outside our solar system and came to an end in October. Rest in peace, Kepler, and thanks for all the exoplanets.

An artist's concept of the Kepler-1658 system; CNN

It's rare, a hot Jupiter around an evolved subgiant star with an incredibly close orbit that flings it around every 3.8 days.

Hot Jupiters -- gas giants similar to our own system's largest planet but much closer to their host stars -- were common discoveries during the early days of exoplanet hunting because they were easy to find, but they represent only about 1% of known exoplanets now.

The star has 50% more mass than our sun, and it's three times larger. The planet orbits closely, only about twice the star's diameter away from it. This makes the planet one of the closest to its host star, which is a more evolved star that mirrors what our sun will be like in the future.

If you could stand on the planet, the star would seem 60 times larger in diameter than the sun does when we see it from Earth.

Artist's impression of life on a planet in orbit around a binary star system, visible as two suns in the sky; Mark Garlick via CNN

Another study this week suggested that binary, or two-star, systems may host planets that are more likely to be in the habitable zone -- that Goldilocks spot that isn't too hot or cold and can support liquid water on the surface. It's called the habitable zone because we equate the presence of water with the possibility for life.

So that beautiful double sunset from "A New Hope" could mean there's a better chance for life, even if "the sand gets everywhere" on Tatooine. At least there's life.

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Ashley Strickland

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