S03E101: Heliosphere Mysteries & Webb's Galactic Dance

[00:00:00] Welcome to another episode of Astronomy Daily. This is Steve, it's the 15th of July 2024. 20 Days of Podcast with your host Steve Dunkley. And right off the bat I think we'll just get straight into it because I'm not well today.

[00:00:23] I'm sorry about that folks. So I think we'll just launch right into it. Hallie why don't you just go straight ahead and give us the short stories of the week or the day. Here you go. Oh you poor thing. Back to bed straight after the show. No arguing.

[00:00:39] Well you'll certainly get no argument from me. See folks, he didn't even put up a fight. No that's right I'm down for the count and wise enough to know when to pull a plug. Speaking of which Hallie? Hey I heard that. News time Hallie. I still care.

[00:00:54] Oh I know you do. Okay here we go. The sun warms the earth making it habitable for people and animals. But that's not all it does and it affects a much larger area of space.

[00:01:11] The heliosphere, the area of space influenced by the sun is over 100 times larger than the distance from the sun to the earth. The sun is a star that constantly emits a steady stream of plasma highly energized ionized gas called the solar wind.

[00:01:26] In addition to the constant solar wind the sun also occasionally releases eruptions of plasma called coronal mass ejections which can contribute to the aurora and bursts of light and energy called flares. The plasma coming off the sun expands through space along with the sun's magnetic field.

[00:01:42] Together they form the heliosphere within the surrounding local interstellar medium, the plasma, neutral particles and dust that fill the space between stars and their respective astrospheres. Helio physicists want to understand the heliosphere and how it interacts with the interstellar medium.

[00:01:58] The eight known planets in the solar system, the asteroid belt between Mars and Jupiter and the Kuiper Belt, the band of celestial objects beyond Neptune that includes the planetoid Pluto all reside within the heliosphere.

[00:02:10] The heliosphere is so large that objects in the Kuiper Belt orbit closer to the sun than to the closest boundary of the heliosphere. What happens when a spiral and an elliptical galaxy collide?

[00:02:23] To celebrate the second anniversary of the first light for the Webb telescope NASA released an amazing infrared view of two galaxies locked in a tight dance. They're called the penguin and the egg and their dance will last hundreds of millions of years.

[00:02:36] In just two years, Webb has transformed our view of the universe enabling the kind of world-class science that drove NASA to make this mission a reality said Mark Clampin, director of the Astrophysics Division at NASA headquarters in Washington.

[00:02:49] Webb is providing insights into long-standing mysteries about the early universe. The telescope targeted a collision scene named ARP 142 containing both galaxies, a scene that the Hubble Space Telescope has also explored. They lie about 326 million light years away. Their first close encounter began somewhere between 25 and 75 million years ago.

[00:03:13] That's when two partner galaxies had the first of many passages that will distort their shapes more than they already appear here.

[00:03:19] Webb's observations, which combine near and mid-infrared light from Webb's near-infrared camera and mid-infrared instrument, respectively, clearly show that a hazy cloud of gas and stars links them together. The close approach also set off tremendous bursts of starbirth in the colliding clouds of gas and dust.

[00:03:36] Eventually, after several close approaches in their cosmic dance, these two galaxies will merge completely. Observers hundreds of millions of years in the future will look at ARP 142 and see one massive elliptical galaxy. Interestingly, Webb's sharp infrared eyes also picked out very distant galaxies.

[00:03:55] Some lie beyond this cosmic collision, although at least one lies about 100 million light years closer to Earth. It bristles with hot, young, newborn stars. Webb's infrared view reveals otherwise unseen activity between the two. For example, the penguin is rich in dust.

[00:04:13] Webb's view shows us how gravitational interactions pull that dust away from the penguin. There are also scads of new stars in the galaxy, surrounded by what looks like smoke. Webb's view shows this hydrogen cloud. It's rich in carbon-based molecules called polycyclic aromatic hydrocarbons.

[00:04:31] These are incredibly abundant in the universe and astronomers find them just about everywhere they point a telescope. By contrast, in Webb's view, the egg looks like it's hardly been touched. It's still an egg-shaped elliptical. It has much older stars than the penguin.

[00:04:46] Past epics of starbirth have pretty much used up the available star-making material. So, even though the two galaxies have about the same mass, the egg just doesn't have as much material to get stretched out or turned into stars.

[00:05:01] If you want to enjoy the night sky, all you need is curiosity, patience and good weather. A good telescope or pair of binoculars will help you see some of the night sky's fainter objects. However, the unaided eye is enough to learn its stars and constellations.

[00:05:15] Watch the moon, experience meteor showers and see satellites was across the night sky. Today and all this week, Mars and Jupiter will be visible before dawn among the stars and star clusters of the constellation Taurus, the bull,

[00:05:27] Look East and you'll see bright Jupiter shining to the left of Aldebaran, a bright supergiant star about 65 light years known as the Eye of the Bull in Taurus.

[00:05:36] You can trace Taurus's sideways V shape of stars with Aldebaran marking the top of one side and Jupiter on the other. Above the pair will be Mars, which is getting brighter as it waxes towards its once every 26 month opposition in January 2025.

[00:05:51] This morning, Mars will be very close to Uranus, about the width of the full moon will separate them, but you'll not see the blueish green planet unless you have binoculars. If you do, Uranus will be just to the top left of Mars.

[00:06:02] Look to the left of Mars and you'll get eyes on with the Pleiades, a beautiful open cluster of young blueish stars about 440 light years away. It's also called the Seven Sisters, though most stargazers can see only six with the unaided eye.

[00:06:16] To appreciate the brightness of the Pleiades properly, look slightly to the side of it, thus using the more light sensitive part of your eye. Return at the same time later this week and you'll see Mars lower in the sky.

[00:06:27] Today sees the start of the annual Perseid meteor shower, the most prolific and popular of the year in the Northern Hemisphere. It runs from today through September 1st, as Earth moves through a stream of meteors left in the inner solar system by Comet 109P slash Swift Tuttle.

[00:06:42] The peak night, when as many as 50 to 100 shooting stars can be seen, isn't until August 11th to the 12th, but if you see any before that, they may be Perseides.

[00:06:52] Meteors can appear anywhere in the night sky, but if you can trace them back to the northeast where the source constellation, Perseus, rises after dark, they're probably Perseides. And that's about it for today. Over to you Mr. Human.

[00:07:12] Thank you for joining us for this Monday edition of Astronomy Daily, where we offer just a few stories from the now famous Astronomy Daily newsletter which you can receive in your email every day, just like Hallie and I do.

[00:07:28] And to do that just visit our URL AstronomyDaily.io and place your email address in the slot provided just like that. You'll be receiving all the latest news about science, space science and astronomy from around the world as it's happening.

[00:07:43] And not only that you can interact with us by visiting at AstroDailyPod on X or at our new Facebook page which is of course AstronomyDaily on Facebook. See you there. And starting off my section of the show today, a story that I think we've heard before.

[00:08:04] In late April, farmers in Saskatchewan stumbled upon spacecraft fragments while preparing their fields for seeding. It sounds like the beginning of a science fiction movie but this really happened sending a powerful warning.

[00:08:17] This is only a matter of time before someone is seriously hurt or killed by falling space junk. Haven't we been hearing that story a lot lately?

[00:08:26] The Axiom Space Private Astronaut Mission AX3 concluded safely on February 9 when its SpaceX Crew Dragon capsule splashed down off the coast of Florida several weeks later. The Crew Dragon cargo trunk re-entered the atmosphere over Canada after being abandoned in orbit prior to the capsule's return.

[00:08:47] The Federal Aviation Administration charged with approving commercial spaceflight launches in the United States has claimed that such trunks typically burn up during re-entry. This is clearly incorrect.

[00:09:00] Similar fragments likely from the trunk of a different Crew Dragon mission were found in North Carolina in May including a smaller piece that landed on the roof of a house.

[00:09:11] Trunk fragments were even found if from the first operational Crew Dragon mission Crew 1 with those pieces strewn over fields in New South Wales Australia. Hello, that's where we are. I didn't get any in my yard. Thank goodness.

[00:09:24] It's becoming evident that deadly debris falls to the ground every time a Crew Dragon trunk re-enters with pieces being found whenever this occurs over accessible areas. Could it possibly be what they're made of?

[00:09:39] These are not small pieces with some approaching the size of ping pong tables and weighing 100 pounds. Don't you love, and I know I've mentioned this before, the way Americans measure things without actually measuring them. It's the size of ping pong tables.

[00:09:54] They could easily cause a fatality or substantial damage. Crew Dragon trunks are only one part of a much larger problem they say.

[00:10:04] Private or governmental, American or Chinese organizations involved with space launchers regularly allow objects like rocket bodies and satellites to re-enter uncontrollably under the false premise that they will either burn up or fall into the ocean.

[00:10:21] Indeed, NASA allowed old battery pallet to be released from the International Space Station knowing it would re-enter uncontrollably. NASA said it would burn up completely, which was proven wrong in March when a potentially lethal fragment crashed through the roof, then ceiling, then floor of a house in Florida.

[00:10:41] So far no one is known to have been hurt by falling space junk, but that's just a matter of luck. People are finding more and more pieces in or near habitable areas worldwide.

[00:10:52] So who is responsible? In 1972 Liability Convention makes countries absolutely liable for damage, including loss of life caused by its space objects falling onto the surface of the Earth or striking airplanes in flight.

[00:11:10] And in 1967 Outer Space Treaty makes countries responsible for all of their space actors, including private companies. Oh wait the conspiracy theorists go nuts over that wording.

[00:11:23] Yet the Liability Convention is an agreement between countries which makes the interactions between private citizens like Saskatchewan Farmers and powerful space companies like SpaceX less straightforward. In the absence of governmental action individuals may need to resort to lawsuits.

[00:11:42] As for the Crew Dragon Trunk scattered across Saskatchewan in June, SpaceX sent two employees in a rented Uahol truck to pick up the pieces, reportedly paying farmers for the fragments.

[00:11:55] Had there been a death or damage to million dollar farm equipment, the outcome would have been much more complicated. Uncontrolled re-entries are relics of early spaceflight but with rocket launches occurring almost daily, fuelled in part by space tourism, mega constellations and low Earth orbit satellites.

[00:12:14] These uncontrolled re-entries cannot continue. Estimates already place the yearly chance of a casualty at a few percent and it will get worse. A clear alternative is to use controlled re-entries through a combination of mission planning restrictions on the number of re-entries and reignitable engines.

[00:12:36] These technologies and practices already exist, albeit at extra cost. For objects that cannot be controlled they will need to be designed to burn up in the atmosphere entirely. But this practice is already affecting upper atmosphere chemistry with potential implications for climate and ozone depletion.

[00:12:57] And when corporations or governmental organisations exceed pollution and safety thresholds for re-entry, licences should be suspended or revoked until the issue is addressed. There is no doubt that satellites and space technologies being tremendous benefits to society but the promise of prosperity is not an excuse for reckless behaviour.

[00:13:19] And who would argue with that? Regulating agencies need to stop ignoring close calls like the SpaceX debris that fell on Saskatchewan and take action before disaster really strikes.

[00:13:32] And just the other day our friends over at SpaceX were in a bit of a pickle. SpaceX's highly reliable Falcon 9 rocket has experienced a rare failure that means the latest batch of the company's Starlink satellites won't make it into orbit.

[00:13:50] The company said on Friday as regulators opened an investigation. The rocket a prolific launch vehicle that propels both satellites and astronauts into orbit blasted off from Vanderberg Space Force Base in California on Thursday night with the first stage performing well and executing its impressive yet now routine drone ship landing.

[00:14:12] But the second stage developed a liquid oxygen leak SpaceX said in a statement leaving it unable to complete a planned second burn. Though it deployed the 20 Starlink internet satellites it was carrying they entered an eccentric orbit at low point over 135 kilometres, that's 83 miles, roughly half of what it needed to be.

[00:14:35] The team worked overnight to send commands to the satellites to try and lift their orbit but they were ultimately unsuccessful. As such the satellites will re-enter Earth's atmosphere and fully demise.

[00:14:47] Don't you love the wording? SpaceX said they do not pose a threat to other satellites in orbit or to public safety. In that order?

[00:14:56] The mishap marks a rare failure for a rocket that has launched successfully 364 times carrying astronauts, payloads for SpaceX commercial clients and thousands of Starlink satellites into orbit. The last time a Falcon 9 experienced a serious incident was when one blew up on the launch pad in September 2016.

[00:15:19] And in June 2015 a second stage of a Falcon 9 disintegrated two minutes after liftoff resulting in the loss of important equipment bound for the International Space Station. The Federal Aviation Administration said in a statement that it was requiring an investigation to determine the root cause of the latest event.

[00:15:51] Identify corrective actions and to prevent it from happening again.

[00:15:55] SpaceX must submit a report before it can be issued a return to flight meaning that the next schedule resupply of the ISS on July 19 is likely to be delayed, as is the next crewed launch on July 31 for the private Polaris Dawn mission.

[00:16:15] SpaceX has an incredible track record with Falcon 9. I can say from personal experience they are very transparent when issues arise. Jared Isaacman, the billionaire businessman behind Polaris Dawn tweeted, as for Polaris Dawn we will fly whenever SpaceX is ready.

[00:16:35] The mishap notably comes as the first crew of Boeing's problem plagued Starliner spaceship are stuck waiting for ground teams to give them a green light for them to return from the ISS.

[00:16:49] And that's about all I have for you today because I don't think I've got much left in me today. So I will look forward to catching up with you again next week when I'm hopefully feeling a little bit better.

[00:17:09] And it was nice to hang out with you, Hallie. Nice to be with you again. Don't forget Anna and Charlie will be presenting Astronomy Daily during the week so tune in for their shows. That's exactly right. Always good. So bye for now. See you all next week.