S02E14: Sky-Watching Delights // Earth's Shifting Axis // Space Force Collaboration // Air Taxi Simulators

[00:00:00] Welcome to Astronomy Daily for the 19th of June 2023. It's lovely to have you with us and also it's lovely to have Hallie with us again. Hi everyone. The 20th day of the podcast with your host Steve Dunkley. What's in store today Hallie?

[00:00:20] Well I know you've got another one of your favorites. Oh and what's that Hallie? You can't help yourself when Space Force makes an announcement. Yes I know, I should be more polite about it shouldn't I? And NASA is testing out some interesting air taxi simulator thingy.

[00:00:33] Oh technical jargon, yes a thingy. That's to get data for innovators and developers. What else? Well apparently humans are pumping out so much ground water from the earth that it's having global ramifications that we need to worry about. Wait till you hear that one.

[00:00:51] Well that one's all yours. And there's some sky-watching news for the Northern Hemisphere. Yes I was reading about this earlier on. A wonderful interaction of several planets, the Moon and Gemini. Oh better dust off the lenses. Okay let's get to it. Roger that.

[00:01:05] Here's the short takes and sky-watching news. The week sky-watching feast begins Monday evening on June 19th starting at 45 to 60 minutes after sundown. Look low to the west northwest horizon to find a slender crescent moon.

[00:01:24] And directly above it will be Pollux and Castor which are the heads of the twin brothers, Gemini.

[00:01:30] Pollux now appears a little over twice as bright as Castor but Castor is the realest star of Gemini and although it appears as a single star with the unaided eye it is actually a system of six stars.

[00:01:42] In a telescope we see two Castor A and B a furthermore both A and B are themselves doubles though much too close to be separated optically called spectroscopic doubles. And to the south of the main pair is Castor C, a pair of dim red stars.

[00:01:57] Tuesday evening, June 20th, a slightly wider crescent moon will have shifted away to the upper left of the twin stars and will be situated roughly a dozen degrees to the lower right of the bright planet Venus.

[00:02:09] Venus continues to easily outshine everything in the evening sky except for the moon itself. It currently shines at magnitude minus 4.6 compared to Pollux and Castor. Venus outshines these luminaries by a factor of 100.

[00:02:27] Wednesday, June 21st is the summer solstice and the first official day of summer for the northern hemisphere and on this evening the convocation of moon, stars and planets will be at its most attractive to the eye.

[00:02:39] About an hour before the sun sets toward due west look about halfway up in the sky to find the crescent moon.

[00:02:46] Now, if you have binoculars, train them on the moon and look to the left and slightly below the crescent and see Venus appearing as a bright speck of white light against the blue of the daytime sky.

[00:02:57] And once you've located it with binoculars, try to see if you can find it with just your eyes alone. If you have good vision and your sky is transparent and not too hazy, you should have little trouble seeing Venus through the daylight.

[00:03:10] Once the sun has set and the sky darkens, both the moon and planet will command everyone's attention to the western sky for nearly three hours after sunset. But Venus won't be alone on this night. About 4 degrees to its upper left, appearing to shine rather feebly, will be Mars.

[00:03:28] You'll likely need binoculars to see it at all in a bright twilight even after Venus becomes obvious. At magnitude plus 1.7, Mars now only ranks as a second magnitude object and shines more than six magnitudes fainter or about 331 times dimmer than Venus.

[00:03:46] One reason is that Mars is only about half the size of Venus and is currently 200 million miles, 322 million kilometers from Earth compared to just 53 million miles, 85 million kilometers for Venus.

[00:04:01] And situated about a dozen degrees to the upper left of Mars is yet another bright twinkler, the bluish first magnitude star regulus, brightest star of Leo the Lion.

[00:04:11] The moon, now a fat crescent nearly five days past new phase, will form a rather wide isosceles triangle with the star regulus and Mars.

[00:04:20] It will mark the vertex angle with the legs measuring roughly six degrees, formed by the regulus slash moon and Mars slash moonsides of the triangle. And regulus and Mars separated by roughly 10 degrees marks the base of the triangle.

[00:04:34] Keen observers will note that Venus and Mars will only get as close to a complete conjunction as 3.57 degrees during June 19 to July 10. As Paul McCartney put it, Venus and Mars are all right tonight. Happy sky watching. Now I didn't notice you walking at an angle, Steve.

[00:04:55] But this story has me worried. Earth's tilt has changed by 31.5 inches, 80 centimeters between 1993 and 2010 because of the amount of groundwater humans have pumped from the planet's interior. During that time humans removed 2,150 gigatons of water from natural reservoirs in the planet's crust.

[00:05:16] If such an amount was poured into the global ocean, its surface would rise by 0.24 inches, 6 millimeters. A new study has now revealed that displacing such an enormous amount of water has had an effect on the planet's axis of spin.

[00:05:30] Scientists arrived at this conclusion by modeling the changes in the position of Earth's rotational pole, the point at which the planet's imaginary axis would stick out of the surface if it were a physical object.

[00:05:43] The position of the rotational pole is not identical with the geographical north and south poles and actually changes over time, so the rotational axis cuts through different spots on the planet's crust at various points in time.

[00:05:55] Since 2016, scientists have known that the rotational pole is affected by climate-related processes, such as the thawing of icebergs and the redistribution of the mass of the water locked in them. But until the researchers added the pumped-out water into their models, the results hadn't perfectly matched observations.

[00:06:14] Without the pumped-out groundwater, the model was off by 31 inches, 78.5 centimeters. Earth's rotational pole actually changes a lot. Qioncio, a geophysicist at Seoul National University who led the study, said in a statement.

[00:06:31] Our study shows that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole. Since the tilt of Earth's axis can have an effect on seasonal weather on the planet's surface,

[00:06:44] scientists now wonder whether the shifts of the rotational pole could contribute to climate change in the long term. And that's all from me for now. Words of that control, we are listening to Astronomy Daily, the podcast.

[00:07:22] If you're interested, you can catch all of the episodes of Space Nuts. Our parent podcast with Andrew Dunkley and Professor Fred Watson at that same address, spacenuts.io. And you can also join us with chats anytime you like.

[00:07:37] Please leave your photographs of anything that's happening in your skies. We are so interested. The community is just growing at a rate of knots. So please join in. We'd love to hear from you. That's at Space Nuts podcast on Facebook. We'd love to hear from you.

[00:07:53] Ah, yes, there's a music. Space Force. U.S. Space Force wants private companies to help it counter emerging threats in space. Officials hope the Cosmic Center will allow the Space Force to take advantage of the thriving commercial space industry.

[00:08:14] U.S. Space Force is seeking to maintain space superiority by opening a new office that will help it partner with the private sector to acquire new technologies more quickly. A ribbon-cutting ceremony held June 6 marked the official opening for Space Systems Command,

[00:08:30] SSC, New Commercial Space Marketplace for Innovation and Collaboration Office or Cosmic. It's in Chantilly, Virginia, and the facility will serve as headquarters for SSC's commercial space office, Cosmo, which was established last year to bolster relationships between Space Force and private sector to capitalize on emerging technologies.

[00:08:53] SSC and the U.S. Space Force Organization for Development and Acquisitions and Open Cosmic in partnership with Virginia Tech Applied Research Corporation and in cooperation with Air Force Research Laboratory, Air Force Office of Scientific Research.

[00:09:12] Cosmic's debut comes amidst an ongoing shift in strategy at SSC as they begin to pivot from developing their own technologies to strengthening partnerships with private companies in opening remarks at the ribbon-cutting ceremony.

[00:09:26] Space Force Major General Steve Whitney said that as service transitions from a small number of larger, more vulnerable satellites to constellations of smaller, more expendable ones, institutions like Cosmic are more important than ever. And you can see the transition to different technologies as an interesting strategy there.

[00:09:48] USSF Colonel Rich Kinsley serves as a senior material leader and runs Cosmic. Kinsley said that Cosmic provides a place and a means for us to get together and best collaborate on commercial space capabilities, warfighter requirements and how to best deliver those capabilities.

[00:10:10] Cosmic spans 10,000 square feet or 929 square meters in real measurements and includes office space and conference spaces that are geared towards commercial outreach services. Acting Director for AFRL Office of Scientific Research, US Air Force Colonel Janelle Jackson

[00:10:31] stressed that importance of Cosmic's initiative saying that the US faces an increasing threat of military competition. Our competitors and adversaries are rapidly moving to challenge and surpass the US science and technology advantage and gain superiority in the air and space domains.

[00:10:50] Taking an integrative approach, she says, by partnering with industry and academia are one of the many ways we can lead the challenge. Interesting stuff from Space Force. To create a future where air taxis are a regular form of transportation, passengers need to be comfortable.

[00:11:11] That's why researchers at NASA's Armstrong Flight Research Center in Edwards, California are exploring how passengers may experience an air taxi ride by building a custom virtual reality flight simulator. NASA is currently researching the human physiological response to motion, vibration, noise and visual stimuli

[00:11:31] that passengers may experience during an air taxi flight and new simulator is a major part of that effort. It includes virtual reality goggles, depicting an aircraft cabin and city environment as well as noise and seat motion to simulate a air taxi ride.

[00:11:48] NASA will make data collected with the simulator available to industry and other stakeholders to help shape the design of electric air taxis, locations where the aircraft will take off and land and desired flight paths through cities.

[00:12:06] In the 70s, NASA was instrumental in developing passenger ride quality metrics for jet airliner noise, seat vibration and motion sickness through human subject testing using unique passenger ride quality simulators located at NASA's Langley Research Center.

[00:12:24] The research center said Kurt Hansen, he's the senior flight controls researcher of this project and he says now NASA's Armstrong Flight Research Center is taking this technology into the 21st century. That's a good thing.

[00:12:40] During an experiment, the test subjects will be secured into the seat on top of a platform that can move in six axes to realistically simulate motion

[00:12:50] and aircraft and tests will gauge their level of discomfort. They will wear virtual reality headsets and headphones to fully immerse them in the experience. It sounds a lot like the kinds of things they did with the astronaut training. It sounds like a lot of fun to me.

[00:13:08] And I guess that if you looked in a lot of bedrooms these days, you would see kids with virtual reality headsets on already doing this kind of thing. So maybe they should tap into that sort of feed as well. They might learn a thing or two.

[00:13:24] And so ends another episode of Astronomy Daily. Thank you so much for joining us again. This has been Steve Dunkley and my trusty digital cohort Hallie. See you all next time. Thanks for joining us. We'll see you again next Monday.

[00:13:40] Don't forget Tim Gibbs on Friday all the way from Bath in England. And we wish you a very happy week of sky gazing. Bye for now.