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I spent this morning watching a spacewalk by a pair of American astronauts. They were doing some work on the International Space Station. It’s the sort of “common” work that, in a few decades, will be “the daily grind” for people living and working in space. As I write this, I’ve got the HDEV camera view of Earth floating by on my second monitor, approximating the “Overview Effect” from my office.

In a very short time (compared to the length of human history), we’ve gone from being land-based beings to space explorers. To be sure, we’ve only gone to space between here and the Moon (and, of course, TO the Moon, 50 years ago). But, we’ve opened up space exploration for all kinds of people. There are a bunch of them passing overhead various bits of Earth’s surface every hour and a half. The International Space Station represents the first and best example of international cooperation of space explorers in our history. It has hosted hundreds of astronauts from around the world. They go up, they do work, they live in space, and after a time, they come back to Earth to continue their work.

“Little Kid” Spacewriter would find all this hard to believe. She began looking to the stars during the Apollo mission build-up. She dreamed of being an astronaut, like so many other kids since then. I once got a letter from a young lady in Zimbabwe when I was a graduate student, looking for information about NASA. She proudly informed me that she wanted to work at NASA and fly to space. I sent along information and encouragement because, to me, anybody’s dream of going to space should be encouraged. I do mean everybody.

China and Space Exploration

That brings me to China and the China National Space Administration (CNSA). I haven’t written a lot about Chinese space ambitions, and it’s high time I took a closer look at their projects.

I did some work with a science and technology museum in Shanghai as a content advisor a year or so back. It was mostly about astronomy and space exploration for exhibits. I was anxious to learn as much from our Chinese colleagues about their space program as I could share from them about ours. My counterparts were quite surprised that I was interested in it. I shared a copy of my book Space Exploration: Past, Present, and Future. It contains a general look at the Chinese space program.

They’re quite proud of their program. And why not? Many I talked to are as space-mad as I am. Their county is doing something cool and exciting. It was an interesting time and we all enjoyed sharing what we knew about space exploration.

The country’s program is a pretty robust one. The CNSA is responsible for all launches (satellites and other payloads). It also coordinates with private launch services (which DO exist in the country). China has its own fleet of satellites for various functions, as well as a rocket program built to further its ambitions in space.

China to Space

So, what’s China doing in space these days? Let’s take a look at some highlights. In late December, for example, CNSA launched its largest carrier rocket, the Long March-5. It is the workhorse “heavy lifter” of the country’s rocket program. Of course, the Chinese take great pride in their work and are rapidly becoming the third-largest space power. Like the U.S., Russia, and others, they continually test their rockets and other hardware, usually with great success.

Long March-5 heads to space, carrying a satellite payload. — The December 27 launch of Long March-5, carrying the Shijian-20 technological experiment satellite. Photo by ???

To Near-Earth Space Orbit and the Moon

In recent years, among its other space aims, the Chinese program has focused on activities on the Moon. Its Chang’e-4 lander and rover are studying the lunar far side and have been doing so since 2018. It will be joined by Chang’e-5 later this year. I previously wrote about the Chang’e-3 lander and its successful lunar landing. The new mission will work on several tasks, including gathering up samples of lunar soil. Eventually, they’ll be brought back to Earth for study.

But, that’s not all that China wants to do in space. You’ve probably heard about their space station, Tiangong. Tiangong 2, the latest version of their station, deorbited in 2018. A new modular space station is planned for low-Earth orbit. Crucial parts are headed to space starting later this year as part of the Tiangong program. The large core module called Tianhe (which means “Harmony of the Heavens” in Mandarin) is first. Other pieces will be added on, later. They include an experiment module (for science research) called Mengian (“Dreaming of the Heavens”). There is also Wentian, another experiment module. Its name means “Quest for the Heavens”. Finally, there is also a space telescope associated with the station, called “Xuntian” (“Heavenly Cruiser”).

To support the construction, China has been testing its Long March rocket family, which will be used to loft bits of the station into orbit. Here’s a good video that covers much of China’s intentions for the near future in space.

Beyond Near-Earth Space?

China also has set its aim on Mars and other parts of the solar system. I’ll write in more detail about its Martian ambitions in my next entry. And, they aren’t the only ones reaching out to the stars. In all, when I was writing my book, I counted 72 countries (at the time of writing) with space programs or startups in space exploration. Spacefaring activities are no longer limited to the “big kids” club here on Earth. Nor should they be. Humanity’s future IS in the stars. After all, the stars are where we came from, long ago.

Everybody’s been in a lather about one of the most famous stars in the sky. That would be Betelgeuse and its “mysterious” dimming or “fainting” that is catching astronomers’ attention. I’ve seen a lot of headlines about how scientists are perplexed or confused or whatever by this star losing some brightness. Even worse are the headlines about how it’s acting strangely, or that its behavior is very weird or that it’s about to explode.

So, I started digging around about it because whenever I see clickbait headlines, I know that somebody didn’t understand the astronomy. Turns out that Betelgeuse is pretty much acting as it has throughout its later life. That’s offering astronomers more insight into its late-stage behavior, which gives a peek at how old, massive stars age and eventually die.

Betelgeuse, which is the bright left “shoulder” of the constellation of Orion, is a variable star. That means it pulsates in brightness over time. It goes from being the eleventh-brightest star in the sky to being not even in the top twenty brightest stars. Right how, it is, in fact, the faintest it’s been more than a hundred years. Sounds pretty interesting, no? It certainly is if you’re a variable star researcher.

chart of Orion showing location of Betelgeuse — A chart view of the stars of Orion, showing Betelgeuse in the shoulder of the giant. The three belt stars run through the middle, and just below them is the Orion Nebula starbirth region. Courtesy Zwergelstern on Wikimedia Commons.

It turns out that Betelgeuse goes through several cycles of dimming and brightening over time. These are due to changes in size and temperature. It’s also possible that the current dimming is being caused by an outburst of material from the star that’s partially obscuring our view. A lot of stars “huff off” material as they age and that stuff creates a shell around the star. That would cause it to appear dimmer to us because some of the light is absorbed or blocked by the material in the shell.

artist concept of Betelgeuse showing its size and possible "look". — An artist’s conception of what Betelgeuse looks like, and its size compared to other objects. It’s one of many supermassive red giants that will eventually collapse in part of supernova events. Credit: ESO/L Calcada

Behavior of Cranky Old Stars

Apparently all of this is completely normal for Betelgeuse. It’s an aging supermassive star and objects like that are cranky as they get older. They oscillate and spew. And, eventually, they blow up. So, does all this dimming and mass loss mean that Betelgeuse is about to explode as a supernova? Probably not. Although, to be fair, going supernova IS the end state for this star. But, it’s not likely to happen for a while.

It might be as little as around a hundred thousand years before this aging red supergiant collapses in on itself and then bursts out as a supernova. Or it could take a bit longer. But, it’s not likely to be tomorrow. Or the next day. Or anytime soon. Kind of disappointing to those of us who’d like to witness a relatively nearby supernova in our lifetimes, but that’s the breaks.

What WILL happen when Betelgeuse gets to its bursting point? Its core will collapse when it runs out of fuel to sustain fusion reactions. The weight of all the layers of gas above it will cause them to crash in on the core. There will be a huge bounce (a rebound) and a lot of Betelgeuse’s material will burst out in a catastrophic explosion. That’ll spread “star stuff” throughout its neighborhood. It won’t all be gone, though. The heavily smashed core will remain, most likely as a neutron star. There won’t be enough mass for it to form a black hole, unfortunately. But, the fireworks show will be a great one, for our great-great-great^n grandkids. They’ll see it from Earth at a relatively safe distance of about 642 light-years.

Another Cranky Type of Star

While Betelgeuse grabs all the attention, another type of star IS going to explode by century’s end. It’s called binary star V Sagittae (V Sge), and it’s not just one star. It’s in a class of object called a “cataclysmic variable binary star”. V Sge has a rather ordinary star orbiting in a binary dance with a white dwarf star. The regular star is losing mass, which is falling onto the white dwarf. That action is powering a hugely powerful stellar wind, as well. Scientists have recently announced that this star is going to give us quite a light show by century’s end. At that point, it will become the most luminous star in the galaxy. It’ll be at least as bright as Sirius, which is currently the brightest star in our night-time sky. It’ll be quite the spectacle.

artist's concept of binary variable star. — Artist’s concept of a binary star; in the case of V Sge, the normal star is much more massive than its white dwarf neighbor, and has lots of mass to “dump” on the dwarf. There are many binary stars in our galaxy and beyond. Courtesy NASA.

The action will start long before V Sge is set to explode. It won’t just flare up suddenly. We’ll have plenty of warning. Over the next decades, It will brighten up quite a bit. About the year 2083, the accretion of material from the normal star to the white dwarf will speed up. That will dump a LOT of material onto the white dwarf.

The fate of the normal star isn’t a good one. It will spiral in toward its white dwarf neighbor, losing more and more mass, which will cause them to brighten up. Eventually, the two stars will merge, and the final explosion will take place. What’s left will be a very massive white dwarf with a tightly packed core, and a vast envelope of burning hydrogen around it. The whole thing will be quite a show, and our great-grandkids will watch it from Earth at a very safe distance of about 8,000 light-years.

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