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Re: Great Replacement Theory/Natural Selection (thread)

sci.astro.amateur

Posted: 1 Hour 42 Minutes ago by: Quadibloc

It _is_ true that Charles Darwin acknowledged deriving inspiration from Thomas Malthus, and Malthus' theories led to such regressive consequences as the "Iron Law of Wages": that businesses ought to pay their laborers wages barely above

Re: Ah, you have to LOVE nuclear RTG powered spacecraft (Voyager 1)

sci.astro.amateur

Posted: 6 Hours 17 Minutes ago by: Chris L Peterson

I doubt that would be the right nuclear technology for a 100 kW generator.

Re: Mercury in retrograde motion (thread)

sci.astro.amateur

Posted: 10 Hours 43 Minutes ago by: kellehe...@gmail.com

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/ Observers in this newsgroup must be delighted to be able to put relative motions into proper perspectives for putting the structure and motions of the planets in a Sun-centred system into prop

Re: Ah, you have to LOVE nuclear RTG powered spacecraft (Voyager 1)

sci.astro.amateur

Posted: 12 Hours 54 Minutes ago by: StarDust

I need one for my home! Free energy! Gas heating prices doubled. Next month water price triples because the drought. Ajajaj! šŸ˜­

Re: Ah, you have to LOVE nuclear RTG powered spacecraft (Voyager 1)

sci.astro.amateur

Posted: 14 Hours 37 Minutes ago by: Scott Kozel

What would it take to build a 100,000 watt RTG to power a manned Mars base?

Re: Great Replacement Theory/Natural Selection (thread)

sci.astro.amateur

Posted: 1 Day 5 Hours ago by: Chris L Peterson

The human species will benefit from anybody considering themselves part of a "superior race" committing suicide.

Re: Great Replacement Theory/Natural Selection (thread)

sci.astro.amateur

Posted: 1 Day 11 Hours ago by: kellehe...@gmail.com

Evolutionary sciences (outside Victorian natural selection/racism) would include stellar evolution and the possibility that the solar system emerged from a transition phase of our parent star (supernova). It keeps the structure of the solar

Re: Great Replacement Theory/Natural Selection (thread)

sci.astro.amateur

Posted: 1 Day 15 Hours ago by: StarDust

Amen! https://www.youtube.com/watch?v=2Ptc9qwy-5A&list=PLmx7HMepeSoXU1Az7tDHcaodz4UdsPfex&index=1

Re: Great Replacement Theory/Natural Selection (thread)

sci.astro.amateur

Posted: 1 Day 23 Hours ago by: kellehe...@gmail.com

Maybe some day, reasonable black complexion Americans will face reasonable white complexion Americans and recognise that they all share the same culture under the umbrella of the human race/humanity. It is then they will realise that they

Re: Ah, you have to LOVE nuclear RTG powered spacecraft (Voyager 1)

sci.astro.amateur

Posted: 2 Days 5 Hours ago by: Chris L Peterson

Thank you for making my point.

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 3 Days 6 Hours ago by: Chris L Peterson

I wasn't disagreeing with the article or the existence of a minor engieneering problem here on Earth! I was laughing at one of the regular SAA laughingstocks.

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 3 Days 9 Hours ago by: Quadibloc

I don't disagree with that part of it; but that doesn't mean that the article about Sa'udi Arabia didn't show that some effort is required for a solution. I'm well aware that Rich takes every opportunity to criticize the failings or lim

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 3 Days 9 Hours ago by: Quadibloc

I guess his point is that fan blades move. So if they get clogged up with dust, just having solar panels tilted isn't going to keep them clean. Dust seems to accumulate no matter what you do, if you don't go out there and directly scrub

Great Replacement Theory/Natural Selection

sci.astro.amateur

Posted: 3 Days 13 Hours ago by: kellehe...@gmail.com

This topic was covered a number of years back in this newsgroup, however, I came to understand the basis of the dangerous notion in the succeeding years. It is from the same people who butchered solar system research. Great Replacement the

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 3 Days 21 Hours ago by: StarDust

Static!

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 3 Days 21 Hours ago by: W

My comment and link was completely valid. It's peterson who has trouble staying on-topic.

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 3 Days 21 Hours ago by: W

If you read RichA's comment, you will see that my linked article is on topic. Perhaps if your reading comprehension were better, you would appear less silly.

Re: Ah, you have to LOVE nuclear RTG powered spacecraft (Voyager 1)

sci.astro.amateur

Posted: 3 Days 21 Hours ago by: Chris L Peterson

No, you have to love competent engineering that chooses the appropriate power source for the each mission.

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 3 Days 21 Hours ago by: Chris L Peterson

Who said they don't? You're silly.

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 3 Days 21 Hours ago by: Chris L Peterson

Nope. It's a readily solvable problem, with many possible solutions. Not too far at all. It's just whacko Rich passive-aggressively fetishizing over nuclear powered spacecraft.

Mercury in retrograde motion

sci.astro.amateur

Posted: 4 Days 2 Hours ago by: kellehe...@gmail.com

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/ Unlike the slower moving outer planets which where the direct/retrograde motions were gauged against the stationary field of background stars seen from a faster moving Earth, we see Venus and

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 4 Days 2 Hours ago by: Quadibloc

The article he cited noted that, in the Middle East, about 50% of output is lost from unattended solar panels - so that _is_ quite different than dust and sand being no problem because it just blows off a tilted solar panel. Thus, h

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 4 Days 2 Hours ago by: Chris L Peterson

It's a very solveable "problem". What they're studying is the most effective ways of mitigating an issue. Very different from flat panels sitting on another planet! You're as silly as Rich.

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 4 Days 2 Hours ago by: W

https://www.nrel.gov/news/features/2021/scientists-studying-solar-try-solving-a-dusty-problem.html You might wish to delete your earlier statement to the OP, lest you look silly.

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 4 Days 6 Hours ago by: Chris L Peterson

Why? They are not hard to clean, dust blows off of panels in the denser air of Earth (and because on Earth panels are tipped). You're silly.

Re: Solar panels and dust bowls don't mix

sci.astro.amateur

Posted: 4 Days 11 Hours ago by: StarDust

Last time I heard about the insight, it's drill was stuck. Did they fix it?

Re: The Pleiades (thread)

sci.astro.amateur

Posted: 5 Days 11 Hours ago by: kellehe...@gmail.com

When Mercury travels behind the Sun from right to left, it announces its arrival before it comes with full range of the C3 camera because its light hemisphere faces us while it takes a while to discern its motion as it passes between the Ea

Re: the Rookie. Just one question. SPOILER

sci.astro.amateur

Posted: 5 Days 16 Hours ago by: Ninapenda Jibini

RichA <rander3128@gmail.com> wrote in news:58022655-ef05-47be-a318-3704c2e24b13n@googlegroups.com: That was my thought, too. Though presumably their boss would be familiar with their tactics (having, in all likleyhood, laid them out), k

Nasa rover begins key drive to find life on Mars

sci.astro.amateur

Posted: 5 Days 17 Hours ago by: StarDust

https://www.bbc.com/news/science-environment-61470537

Re: Someone will see the total lunar eclipse tonight

sci.astro.amateur

Posted: 6 Days 4 Hours ago by: StarDust

https://www.youtube.com/watch?v=QuedeuV9WrA šŸ˜­

Re: Someone will see the total lunar eclipse tonight

sci.astro.amateur

Posted: 6 Days 14 Hours ago by: StarDust

Bay Area -Too low on the horizon , would need higher elevation to see it! Just watch it on TiVi! šŸ¤—šŸ¤”

Re: The Pleiades (thread)

sci.astro.amateur

Posted: 6 Days 18 Hours ago by: Quadibloc

He understands... parts of them... well enough. But he refuses to accept that what was observed by Kepler ended up being explained by Newton, who built on methods pioneered by Galileo. To me, at least, this seems like an ideological bli

Re: The Pleiades (thread)

sci.astro.amateur

Posted: 7 Days 2 Hours ago by: kellehe...@gmail.com

Contemporary satellite observations, free from daily rotational influences with the ability to see planets as they actually exist within the framework of a Sun-centred system, obviate the need to appeal to the Ptolemaic framework which the

Re: The Pleiades (thread)

sci.astro.amateur

Posted: 7 Days 6 Hours ago by: Chris L Peterson

The motions have been well described for millennia. And well understood for centuries. By everyone except Gerald, who still doesn't understand them.

Re: super blood Moon (thread)

sci.astro.amateur

Posted: 7 Days 6 Hours ago by: W

"It will look just like Mars with the naked eye at 80x!"

Re: super blood Moon (thread)

sci.astro.amateur

Posted: 7 Days 11 Hours ago by: StarDust

Don't forget to take band aid along!

super blood Moon

sci.astro.amateur

Posted: 7 Days 12 Hours ago by: StarDust

https://www.bbc.com/news/science-environment-61423765

Re: The Pleiades (thread)

sci.astro.amateur

Posted: 7 Days 13 Hours ago by: kellehe...@gmail.com

I will give you credit for not interpreting the difference between Venus as an evening appearance or to the left of the Sun seen from our slower moving planet and when it is to the right of the Sun as a morning appearance as it is present

Re: The Pleiades (thread)

sci.astro.amateur

Posted: 7 Days 17 Hours ago by: palsing

Gerald, don't know why you don't understand that the motions that you are describing have been well understood for centuries! Neither one of you fellows are the 'first' to affirm this patently obvious fact. This has been "old news" for

Re: The Pleiades (thread)

sci.astro.amateur

Posted: 8 Days 5 Hours ago by: kellehe...@gmail.com

There is magnification and identification as a lovely exercise (even RA/Dec identification), however, there is also magnification and interpretation as a far more satisfying exercise. I knew someone couldn't stay away after the unnecessa

Re: The Pleiades (thread)

sci.astro.amateur

Posted: 8 Days 9 Hours ago by: Mike Collins

The Pleiades

sci.astro.amateur

Posted: 8 Days 12 Hours ago by: kellehe...@gmail.com

The grouping of stars seen from a moving Earth is currently behind the Sun and comes into view within the range of the C3 camera which registers the Earth's orbital motion- https://www.universetoday.com/wp-content/uploads/2015/04/Venus-Ple

Re: Pluto - blow your mind! (thread)

sci.astro.amateur

Posted: 8 Days 21 Hours ago by: fred__k._engelsĀ®

Re: Mercury comes into view (thread)

sci.astro.amateur

Posted: 9 Days 13 Hours ago by: StarDust

Meanwhile, another STAR is born! https://www.youtube.com/watch?v=QuedeuV9WrA

Re: Great. A cheap way to flood the sky with satellites

sci.astro.amateur

Posted: 9 Days 14 Hours ago by: StarDust

Don't worry, only for small LEO sats!

Re: Mercury comes into view (thread)

sci.astro.amateur

Posted: 9 Days 14 Hours ago by: StarDust

Oy vey! https://www.youtube.com/watch?v=JFQuiKLPS6A

Re: Mercury comes into view (thread)

sci.astro.amateur

Posted: 9 Days 23 Hours ago by: kellehe...@gmail.com

Mercury is about to make a return journey between the slower moving Earth and the central Sun in retrograde motion- https://sol24.net/data/html/SOHO/C3/96H/VIDEO/ As Mercury moves faster than the Earth, it will be registered as a backward

Re: Pluto - blow your mind! (thread)

sci.astro.amateur

Posted: 11 Days ago by: Chris L Peterson

Another way of looking at it is simple illuminance, or lumens per square meter (lux). A sunlit landscape on Earth is nominally 75,000 lux. So we're looking at something like 50 lux at Pluto. 50 lux is what typical household room lightin

Re: Pluto - blow your mind! (thread)

sci.astro.amateur

Posted: 11 Days 1 Hour ago by: StarDust

Sat had a big flash light? I guess?

Re: Pluto - blow your mind! (thread)

sci.astro.amateur

Posted: 11 Days 12 Hours ago by: Quadibloc

That's a good question. Light follows the inverse-square law; we know that there's enough sunlight illuminating Pluto that we can see Pluto from Earth in a good telescope. Pluto orbits the Sun at an average distance of 39 astronomical

Pluto - blow your mind!

sci.astro.amateur

Posted: 12 Days 22 Hours ago by: StarDust

https://www.reddit.com/r/space/comments/ul6v1k/plutos_mountains_frozen_plains_and_foggy_hazes/?%24deep_link=true&correlation_id=17fa7b4e-83d7-4236-916f-049036f8e68f&post_fullname=t3_ul6v1k&post_index=1&ref=email_digest&ref_campaign=email_di

Re: Telescopes continue climb in price

sci.astro.amateur

Posted: 13 Days 5 Hours ago by: fred__k._engelsĀ®

The Chicom massive spy satellites continue to climb in number!!!!!!!!!!!

Re: Telescopes continue climb in price

sci.astro.amateur

Posted: 14 Days 5 Hours ago by: W

Two different approaches to being an amateur astronomer: One that involves buying new equipment very rarely. Another that involves buying/selling/trading equipment every minute and a half.

Re: Telescopes continue climb in price

sci.astro.amateur

Posted: 15 Days 12 Hours ago by: StarDust

Who cares? I haven't bought a telescope at least 10 years! šŸ¤‘šŸ¤—

Re: Star Trek Picard. Ode to Star Trek IV, woke style

sci.astro.amateur

Posted: 16 Days ago by: Ace Crysler

Don't know if you watched the final episode, but Seven planted a big kiss on the girl she's been running around with. You/we were right!

Radio Meteor Obs. Bull. April 2022 Lyrids (thread)

sci.astro.amateur

Posted: 17 Days 9 Hours ago by: Chris Steyaert

Radio Meteor Observation Bulletin No. 345 of April 2022 (64 K) is available now as https://www.rmob.org/rmobtext/rmob2204.txt More information and the visual presentation of the hourly forward scatter counts can be found on https://ww

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 19 Days 14 Hours ago by: Chris L Peterson

Surface temperature depends upon material properties, particularly emissivity. Under a clear sky, radiative heating significantly dominates over air temperature. Likewise for cooling. Around here, a bucket of water left outside at night

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 19 Days 16 Hours ago by: Scott Kozel

You mentioned 30 C (87F). Even over 100F here it does not do that. Surface temp is a product of air temp and atmospheric clarity. Something must be wrong with the mix designs.

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 20 Days 9 Hours ago by: Martin Brown

It isn't the air temperature that matters. It is the surface temperature of the black tarmac road which can get too hot to touch and melts. It really only takes a nice still day and a clear blue sky in the summer months and after two o

Iraq dust storm

sci.astro.amateur

Posted: 20 Days 11 Hours ago by: StarDust

https://www.bbc.com/news/world-61292334 Just watch California this summer, when sky turns orange from fires and smog after temp. hit over 40 C!

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 20 Days 15 Hours ago by: Scott Kozel

87 F, not hot at all. Something must be wrong with the mix designs. Pretty rare here but it has happened, usually on the older pavements (1970s, 1980s).

Bealtaine festival and first day of summer

sci.astro.amateur

Posted: 21 Days 7 Hours ago by: kellehe...@gmail.com

This is a wonderful day where the old calendar stretching back to remote antiquity coincides with the present calendar. The year was originally divided into two halves with the dark half from November 1st extending to April 30th and the lig

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 21 Days 9 Hours ago by: Martin Brown

It doesn't liquify as such but it no longer has any shear strength and is torn apart by HGVs and agricultural vehicles in the mid afternoon when the air and road temperature is hottest. It doesn't help that the silage and harvest perio

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 21 Days 10 Hours ago by: kellehe...@gmail.com

Different materials expand at different rates depending on how much radiation they absorb as the Earth turns daily to the Sun- http://prairieecosystems.pbworks.com/f/1179343887/crerar%20temperature%20variation.jpg It is unfortunate that

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 21 Days 14 Hours ago by: Scott Kozel

It has been up to 105 F here, and I haven't seen any liquified asphalt pavement yet. Concrete pavement has been known to expand and blow out.

Re: This hit fairly hard

sci.astro.amateur

Posted: 21 Days 19 Hours ago by: W

That component is expendable. It does not need to land softly.

Re: This hit fairly hard

sci.astro.amateur

Posted: 22 Days 5 Hours ago by: Chris L Peterson

Impracticably large, in fact. Which is why they only used a parachute as part of the slowing down process. The final landing needs to be by rocket, or something aerodynamic, or an energy absorber like those giant airbags.

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 22 Days 6 Hours ago by: Chris L Peterson

I doubt it was that hot. But over 100 F, and mid-day, for sure.

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 22 Days 15 Hours ago by: Scott Kozel

You mean like atmospheric temp is 115-120 F, and the Sun is at high elevation on a clear day?

Re: This hit fairly hard

sci.astro.amateur

Posted: 23 Days 6 Hours ago by: Chris L Peterson

Terminal velocity on Mars is about five times greater than that on Earth. So yeah... things tend to hit hard!

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 23 Days 6 Hours ago by: fred__k._engelsĀ®

Re: Drilling into the ice on Europa (thread)

sci.astro.amateur

Posted: 23 Days 22 Hours ago by: Chris L Peterson

When I lived in California, on hot days you could pick off blobs of tar out of the asphalt and manipulate it like chewing gum.

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 24 Days ago by: Scott Kozel

Well if the atmospheric temp is 115-120 F, and the Sun is at high elevation on a clear day, the radiant heat the Sun could boost the pavement temp over 140 F. I live in an area that occasionally reaches 100 F, and I have not yet seen an

Re: Here we go again (thread)

sci.astro.amateur

Posted: 24 Days 5 Hours ago by: fred__k._engelsĀ®

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 24 Days 13 Hours ago by: kellehe...@gmail.com

You should make the effort to instruct those around you what a planetary transit represents using a stepped reduction in time scales- https://www.popastro.com/images/planetary/observations/Venus-July%202010-January%202012.jpg https://ww

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 24 Days 13 Hours ago by: palsing

Gerald... it is pretty obvious that you do not know what an annular eclipse is... a search engine will help you...

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 24 Days 14 Hours ago by: kellehe...@gmail.com

An eclipse and a transit should be two different things with no ambiguity as a transit and an eclipse are component parts of a larger picture of orbital motion. You brought up this wonderful imaging of Phobos passing between Mars and th

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 24 Days 14 Hours ago by: Chris L Peterson

Asphalt commonly gets well over 140F on hot, sunny days. Fresh asphalt in places like Phoenix can reach 180F. It's a big part of the urban heat island effect.

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 24 Days 16 Hours ago by: Scott Kozel

Correction 138 to 166 C

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 24 Days 16 Hours ago by: Scott Kozel

Asphalt concrete mix designs are in the 280 - 330 F (536-636 C) range for production at the plant to create a molten material that can be transported to the job site. 60 C is 140 F and that would be rare if ever that a pavement got tha

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 24 Days 18 Hours ago by: palsing

Had you said this in your first response this would have been a much shorter thread... šŸ™ƒ

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 24 Days 19 Hours ago by: Chris L Peterson

An annular eclipse is actually a transit!

Re: Here we go again (thread)

sci.astro.amateur

Posted: 25 Days 3 Hours ago by: kellehe...@gmail.com

The creation of the average 24 hour day is an extension of the sunrise/noon/sunset cycles where the proportion is 1461 rotations for 4 orbital circuits using external cyclical references and reduces to 365 1/4 rotations per circuit without

Re: Here we go again (thread)

sci.astro.amateur

Posted: 25 Days 5 Hours ago by: Chris L Peterson

In essence, what we did was change the second from a unit of timekeeping (which Gerald seems to require it to be) to a unit of time. Had we left the second tied to the motion of the Earth (which we could have), we'd simply have needed t

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 25 Days 5 Hours ago by: Chris L Peterson

"Hardness" is one aspect of material strength. Granite is very hard. But that doesn't mean it's difficult to drill into. Some hard materials are easy to work with, some softer ones are difficult. I think ice is one of the easiest materi

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 25 Days 11 Hours ago by: Martin Brown

Concrete is lot harder than Asphalt at STP in a Young's modulus sense. https://www.slowtwitch.com/Training/Running/Concrete_or_Asphalt__4793.html Once the road surface gets to 60+C then asphalt is little different to crushed gravel in

Re: Here we go again (thread)

sci.astro.amateur

Posted: 25 Days 14 Hours ago by: Quadibloc

It is true that changing to the use of atomic time as the basis for our current official system of timekeeping has led to inconveniences like leap seconds. Historically, the second was derived from the solar day. Why didn't we keep thing

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 25 Days 16 Hours ago by: Scott Kozel

Asphalt concrete is hard.

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 26 Days 10 Hours ago by: Quadibloc

Speaking of transits, as we know historically, transits of Venus, viewed from Earth, have been important in determining the dimensions of the Solar System. I don't suppose one of these space probes will have the great good luck of being

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 26 Days 14 Hours ago by: Chris L Peterson

It's just some kind of bot. Ignore it.

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 26 Days 14 Hours ago by: kellehe...@gmail.com

I would say, who can argue against imaging and what their eyes are telling them whether an individual or an institution. The imaging is there for those who can appreciate a planetary transit as distinct from an eclipse rather than dither

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 26 Days 16 Hours ago by: StarDust

Da! Is asphalt hard?

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 26 Days 16 Hours ago by: palsing

As is often the case, Gerald, your response is somewhat garbled. All I can say is that the article that I referenced was written by someone representing both JPL and NASA... and if those towering institutions call it an eclipse, who am I

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 26 Days 16 Hours ago by: palsing

I'm pretty sure that talking about planetary exploration falls under the very broad subject of 'astronomy'...

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 26 Days 16 Hours ago by: palsing

Who died and made you King?

Re: Here we go again (thread)

sci.astro.amateur

Posted: 27 Days ago by: kellehe...@gmail.com

The fundamental unit of timekeeping is a proportion. Timekeeping, including the average/equable 24 hour day and splintered into equable hours, minutes and seconds, is based on a proportion between two cycles. The first reference is a

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 27 Days 1 Hour ago by: Scott Kozel

The chemical characteristics of water ice at cryogenic temperatures is definitely on-topic.

Tiny satellites to index the planet

sci.astro.amateur

Posted: 27 Days 2 Hours ago by: StarDust

https://www.youtube.com/watch?v=Ryt-iyf9b3M&t05s It will solve humanity's problem for sure?

Re: Here we go again (thread)

sci.astro.amateur

Posted: 27 Days 2 Hours ago by: Chris L Peterson

The second is a unit of time which is historically related to primitive timekeeping methods, but is now attached to physical constants, so that any technological species in the Universe could understand and replicate it. All other units

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 27 Days 4 Hours ago by: fred__k._engelsĀ®

Ok, goodnight folks. lock.gif This topic has obviously run its course.

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 27 Days 4 Hours ago by: Scott Kozel

Granite is hard enough that it can be used as aggregate in concrete and asphalt and used to build highway pavement that can carry thousands of large trucks per day.

Here we go again

sci.astro.amateur

Posted: 27 Days 4 Hours ago by: kellehe...@gmail.com

https://www.nytimes.com/2022/04/25/science/time-second-measurement.html The second is not a unit of time, it is a unit of timekeeping with a very specific trajectory of historical events leading to its adoption along with the equable minu

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 27 Days 6 Hours ago by: kellehe...@gmail.com

It would seem an eclipse is primarily when a moon passes between the planet and the central Sun in its orbit of a planet. A transit is when a planet passes between another planet and the central Sun in its orbit of the Sun. The time la

Representing a transit

sci.astro.amateur

Posted: 27 Days 10 Hours ago by: kellehe...@gmail.com

A planetary transit is part of a large process that can be neatly summarised by different imaging stages. Take Venus, for example. https://www.popastro.com/images/planetary/observations/Venus-July%202010-January%202012.jpg That represents

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 27 Days 14 Hours ago by: StarDust

Actually, granite is not that hard! Diamond coring drill goes through it like butter. Done that, when through holes had be drilled into precision granite surface plate, because measuring instruments were mounted to it!

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 27 Days 14 Hours ago by: Scott Kozel

Water ice at cryogenic temperatures is almost as hard and tough as granite.

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 27 Days 23 Hours ago by: Ninapenda Jibini

Chris L Peterson <clp@alumni.caltech.edu> wrote in news:2bma6hpjt46e2uktqcg5n3fftd7a5jtu8g@4ax.com: The pump would be a good source of heat for the melting part. Though pumping liquid water for multiple kilometers would take quite a lo

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 28 Days 2 Hours ago by: StarDust

Easier than through your skull, for sure!

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 28 Days 4 Hours ago by: Martin Brown

I was envisaging minimum energy solution which is allow the melt water slush to freeze behind the probe. It might well work - certainly a lot more bandwidth that way.

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 28 Days 4 Hours ago by: Chris L Peterson

I wouldn't say it's splitting hairs. This is not an eclipse, very much by the formal definitions of both "eclipse" and "transit". (An annular eclipse is also a transit... we really only use the term because the same conditions that gener

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 28 Days 4 Hours ago by: W

If a discernible shadow is involved, then it should be an eclipse.

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 28 Days 5 Hours ago by: Chris L Peterson

You'd also need to pump the meltwater back up to the surface, and keep it from freezing on that trip... which might take quite a lot of energy. Assuming you want to keep the channel open. Or... maybe your probe carries a spool with a fe

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 28 Days 6 Hours ago by: Martin Brown

That is splitting hairs - it is close enough to being an annular eclipse given the dimensions of the sun and moon. Rather a nice video.

Re: Drilling into the ice on Europa

sci.astro.amateur

Posted: 28 Days 6 Hours ago by: Martin Brown

If you don't care about being able to transmit a signal back out again then being able to maintain a temperature above 1C and wait would probably be good enough. The warmer it is the better rate of progress but not too hot. Sort of thi

Re: Solar Eclipse from Mars (thread)

sci.astro.amateur

Posted: 28 Days 8 Hours ago by: P

very very cool!!!

SN1987a and Webb

sci.astro.amateur

Posted: 28 Days 12 Hours ago by: kellehe...@gmail.com

https://www.nasa.gov/feature/goddard/2019/nasas-webb-telescope-will-study-an-iconic-supernova There is a possibility, by putting together a narrative from different supernova events, that the magnificent explosion of a certain pre-supernov

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