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I think it is quite likely that we will find a goldilocks planet relatively soon. But I doubt if it will have more than unicellular "life". Most people immediately jump to the conclusion that life means advanced animal life. Thats the danger with generalised definitions like "goldilocks planet". It rises expectations far too high.
I would be happy just to find unicellular life, however, I don't know how we would be able to detect it. If there is an advanced civilization that we can talk to that would convince us that life existed on those exoplanets.
Well, there is no evidence that there is an advanced civilisation on one of the moons of Saturn, the one which has methane seas on it. See this Wikipedia item of the moons of Saturn: https://en.wikipedia.org/wiki/Moons_of_Saturn.
I think it is pretty well established that there is no civilisation anywhere that is at all near to Earth, as far as we can tell.
Perhaps if NASA is planning a more detailed investigation of Mars they might come up with something. I believe water is found underground om Mars. See http://motherboard.vice.com/blog/mar...gy-underground, though only traces, no seas.
In the solar system, the most I would expect to see are microorganisms. At least we can get to those objects. But further out, I don't know how we would tell there are microorganisms on an exoplanet.
No, I agree.
Earth Trojans are asteroids that circle the sun in the vicinity of the Earth-Sun Lagrangian Points. see https://en.wikipedia.org/wiki/Earth_trojan.
See also this article on Earth-Sun's only know Earth Trojan: http://news.nationalgeographic.com/n...space-science/.
See also this article on Earth Trojans: http://planetfacts.org/trojan/
Make sure you read the links if anything is unclear.
Earth Trojans:
An Earth trojan is an asteroid that orbits the Sun in the vicinity of the Earth–Sun Lagrangian points L4 (leading 60°) and L5 (trailing 60°), thus having an orbit similar to Earth's. Only one Earth trojan has so far been discovered. The name trojan was first used in 1906 for the Jupiter trojans, the asteroids that were observed near the Lagrangian points of Jupiter's orbit.
Tiny companion will remain tied to our planet for at least ten thousand years, experts predict.
A tiny space rock that's partially tethered to Earth by a gravitational leash is our planet's first known Trojan asteroid, astronomers say.
A Trojan, in Astronomy, is a minor planet or moon that shares an orbit with a larger planet or satellite but does not collide with the larger planet because while it orbits, it stays safely in what is called as the Lagrangian points. In theory, there are also Trojan planets that may reside at Trojan points.
Lagrangian points are five spots in any space where the gravitational pull of two relatively massive bodies, as in the case of a Sun and a planet are balanced out, making it possible for smaller bodies like moons, minor planets and asteroids to remain fixed, in essence, with respect to the planet. The smaller objects still move but they are locked into a synchronized orbit due to the gravities exerted by the two large bodies. Thus, collisions are avoided. However, only two of the five Lagrangian points located around 60 degrees of the planet at any point (L4 and L5) are stable and smaller objects and bodies tend to collect in the area. L1, L2 and L3, on the other hand are unstable, causing rapid object displacement.
The most popular Trojans in astronomy are those discovered around Neptune. They are so numerous that they are believed to be more than the asteroid count in the Asteroid Belt between the inner and outer planets. There are currently 6 known Trojans in the L4 point of the Neptune’s orbit. There are few identified Trojans because they are very faint as not only are they small, they are also too far from the Earth and the Sun. Studying Trojans help astronomers in understanding how planets and the planetary systems, such as the Solar system evolved.
The three links together can be understood by combining them into the three posts as I have done here.
I think this is fascinating...
On the one hand the discovery of this 300 meter trojan in the Earth's orbit in 2010 makes me think that we do not know much about the solar system. On the other, this object is only 300 meters in diameter which isn't very large.
Earth is only a minor planet, the bigger ones like Jupiter and Saturn have more.
The possibility of water on Mars' surface has been questioned. See the post below: http://www.space.com/35071-mars-dark...er-debate.html
More on Trojans: EarthSky report that a probe will search for more. See http://earthsky.org/space/osiris-rex...ojan-asteroids
I can see how more massive planets would have more trojans.
Thats what I said. What about the other questions?
It easier if you quote the post you are addressing...
I am just agree with you. I am glad to see the OSIRIS_REx spacecraft can get a closer look.
So Lagrangian points 1,2 and 3, all in one straight line with sun and earth, are barely stable, and points 4 and 5, 60° ahead of us and behind us in our orbital path, are highly stable. We have a cool one and a hot one a million miles on either side of us directly in line with us and the sun which are barely stable. Not much use is projected for point 3 on the far side of the sun, where the legendary (fictional) planet X is supposed to be. If there were a planet our size there, they would probably reason that any planet in our position would have an unstable orbit, so there is probably not one where we are. Ahem!Quote:
Originally Posted by Dreamwoven
At least points 1 and 2 are stable enough for space equipment to reside. At point 2 no special cooling equipment is required, which simplifies a mission. Points 4 and 5 are great prospects for some asteroids we can mine or for settlement. Any news of those locations will be of keen interest to any who read this thread.
Which brings me to a question: If these are the famous Lagrangian points and the nearest are a million miles away, what are these stable points that Arthur C. Clarke was responsible for predicting where we now keep many satellites parked? Are these too Lagrangian points, but points from a separate deal between the earth and moon? These points are only about 22000--26000 miles from earth, I believe. These points seem to represent "gravity wells," as well, just like their bigger brothers, if that is even what they are. Do you know anything about that?
I answered my own question. They seem mechanically separate phenomena, though they could be confused as related. An object in obit around earth at a Clarke point travels around us at the same rate we rotate on our own axis. The net result is it stays in one place above a point on the equator through night and day with us. If Clarke points and Lagrangian points have a relationship, I do not see it. I know almost no mathematics of celestial mechanics, so there could easily be a relationship I do not see.
Hmm, my understanding of Lagrangian Points is that they exist between all planets, suns, and any space object that has its own gravity. I don't know anything about Clarke Points as mathematical phenomena, though.
Hmm, my understanding of Lagrangian Points is that they exist between all planets, suns, and any space object that has its own gravity.
I can't find anything helpful on Clarke points. Only this website in Wikipedia but in Swedish on Clarke Points: https://sv.wikipedia.org/wiki/Clarke_Point
http://www.universetoday.com/132413/...saturns-moons/
Extracts from this post. read the whole article at the above link.
Welcome back to our series on Colonizing the Solar System! Today, we take a look at the largest of Saturn’s Moons – Titan, Rhea, Iapetus, Dione, Tethys, Enceladus, and Mimas.
From the 17th century onward, astronomers made some profound discoveries around the planet Saturn, which they believed was the most distant planet of the Solar System at the time. Christiaan Huygens and Giovanni Domenico Cassini were the first, spotting the largest moons of Saturn – Titan, Tethys, Dione, Rhea and Iapetus. More discoveries followed; and today, what we recognized as the Saturn system includes 62 confirmed satellites.
What we know of this system has grown considerably in recent decades, thanks to missions like Voyager and Cassini. And with this knowledge has come multiple proposals that claim how Saturn’s moons should someday be colonized. In addition to boasting the only body other than Earth to have a dense atmosphere, there are also abundant resources in this system that could be harnessed.
Much like the idea of colonizing the Moon, Mars, the moons of Jupiter, and other bodies in the Solar System, the idea of establishing colonies on Saturn’s moons has been explored extensively in science fiction. At the same time, scientific proposals have been made that emphasize how colonies would benefit humanity, allowing us to mount missions deeper into space and ushering in an age of abundance!
On March 9th, 2006, NASA’s Cassini space probe found possible evidence of liquid water on Enceladus, which was confirmed by NASA in 2014. According to data derived from the probe, this water emerges from jets around Enceladus’ southern pole, and is no more than tens of meters below the surface in certain locations. This would would make collecting water considerably easier than on a moon like Europa, where the ice sheet is several km thick.
Data obtained by Cassini also pointed towards the presence of volatile and organic molecules. And Enceladus also has a higher density than many of Saturn’s moons, which indicates that it has a larger average silicate core. All of these resources would prove very useful for the sake of constructing a colony and providing basic operations.
In October of 2012, Elon Musk unveiled his concept for an Mars Colonial Transporter (MCT), which was central to his long-term goal of colonizing Mars. At the time, Musk stated that the first unmanned flight of the Mars transport spacecraft would take place in 2022, followed by the first manned MCT mission departing in 2024.
In September 2016, during the 2016 International Astronautical Congress, Musk revealed further details of his plan, which included the design for an Interplanetary Transport System (ITS) and estimated costs. This system, which was originally intended to transport settlers to Mars, had evolved in its role to transport human beings to more distant locations in the Solar System – which could include the Jovian and Cronian moons.
As far as colonizing those places go, it seems more useful to put satellites around them or send probes to their surfaces. They could be our eyes. I suspect mining could have some value if there is something there that we need on Earth.
It was interesting reading about setting up a greenhouse effect on Mars to warm it up so it would be more habitable for us to get there, however, controlling the greenhouse effect on any planet including our own might be useful for those planets already in the habitable zone. If we can terraform Mars we should be able to terraform Venus and have the technology to make sure Earth stays terraformed when it gets closer to the Sun. I think the best solution would be a set of satellites that reflected away radiation from the Sun or focused it depending on the degree of greenhouse effect we wanted to achieve. We should experiment with the Moon first.
Absolutely Lagrange points exist around all massive objects. Here is the other point that Clarke first suggested. They are known as geostationary orbits. They are a different phenomenon from the Lagrange points because they stay with a single point on our equator as that point moves through night and day, while the Lagrange points are stationary (except for moving with us in orbit) and all points of our equator pass beneath them (assuming, that is, that they are aligned with our equator, which I do not know for sure).Quote:
Originally Posted by Dreamwoven
As I think about it, I am starting to believe the Lagrange points would not be oriented above our equator at all, but about the Great Circle (a mapping term) which would be our equator without tilt. It is an interesting question which I have to find out though I am now pretty sure the Lagrange points would care nothing at all for our equator, any more than they would align themselves with some of the highly eccentric planetary orbits found in our solar system. Our home pair are a million miles away. No, they would not care about our little equator. Sometimes you answer your own questions.
So Lagrange Points would be the best places to locate space telescopes, like Hubble and Spitzer. Makes sense!
Quote:
Originally Posted by desiresjab
About the "warm Neptun", a new planet:
"A pioneering new study uncovering the 'primitive atmosphere' surrounding a distant world could provide a pivotal breakthrough in the search to how planets form and develop in far-flung galaxies.
[/I]The atmosphere of the distant “warm Neptune” HAT-P-26b, illustrated here, is unexpectedly primitive, composed primarily of hydrogen and helium. By combining observations from NASA’s Hubble and Spitzer space telescopes, researchers determined that, unlike Neptune and Uranus, the exoplanet has relatively low metallicity, an indication of the how rich the planet is in all elements heavier than hydrogen and helium.[/I]
Credit: NASA/GSFC
At:https://www.sciencedaily.com/release...0511141951.htm
That article gives a nice description of "metallicity". I didn't know so much could be known about an exoplanet's atmosphere.
Neither did I, Yes/No. One of the things that fascinates me is that these new planets that are discovered are a challenge to the astronomers theories. It´s not so long ago we knew about a solar system that now seems so modest in the light of the new discoveries. Now we know even about the atmosphere of very distant planet.
What’s on the Surface of Venus?
by Fraser Cain
We’re always talking about Mars here on the Guide to Space. And with good reason. Mars is awesome, and there’s a fleet of spacecraft orbiting, probing and crawling around the surface of Mars.
The Red Planet is the focus of so much of our attention because it’s reasonably close and offers humanity a viable place for a second home. Well, not exactly viable, but with the right technology and techniques, we might be able to make a sustainable civilization there.
We have the surface of Mars mapped in great detail, and we know what it looks like from the surface.
But there’s another planet we need to keep in mind: Venus. It’s bigger, and closer than Mars. And sure, it’s a hellish deathscape that would kill you in moments if you ever set foot on it, but it’s still pretty interesting and mysterious to visit.
Would it surprise you to know that many spacecraft have actually made it down to the surface of Venus, and photographed the place from the ground? It was an amazing feat of Soviet engineering, and there are some new technologies in the works that might help us get back, and explore it longer.
Venera 10 image of Venusian surface (1975). 174-degree raw 6-bit logarithmically encoded telemetry seen above. Linearized and aperture corrected view in center, including data from a second 124-degree panorama. Bottom image had missing portions in-painted with Bertalmio's algorithm.
Today, let’s talk about the Soviet Venera program. The first time humanity saw Venus from its surface.
Back in the 60s, in the height of the cold war, the Americans and the Soviets were racing to be the first to explore the Solar System. First satellite to orbit Earth (Soviets), first human to orbit Earth (Soviets), first flyby and landing on the Moon (Soviets), first flyby of Mars (Americans), first flyby of Venus (Americans), etc.
The Soviets set their sights on putting a lander down on the surface of Venus. But as we know, this planet has some unique challenges. Every place on the entire planet measures the same 462 degrees C (or 864 F).
Furthermore, the atmospheric pressure on the surface of Venus is 90 times greater than Earth. Being down at the bottom of that column of atmosphere is the same as being beneath a kilometer of ocean on Earth. Remember those submarine movies where they dive too deep and get crushed like a soda can?
Finally, it rains sulphuric acid. I mean, that’s really irritating.
Needless to say, figuring this out took the Soviets a few tries.
Venera 1
The Venera 1 spacecraft
Their first attempts to even flyby Venus was Venera 1, on February 4, 1961. But it failed to even escape Earth orbit. This was followed by Venera 2, launched on November 12, 1965, but it went off course just after launch.
Venera 3 blasted off on November 16, 1965, and was intended to land on the surface of Venus. The Soviets lost communication with the spacecraft, but it’s believed it did actually crash land on Venus. So I guess that was the first successful “landing” on Venus?
Before I continue, I’d like to talk a little bit about landing on planets. As we’ve discussed in the past, landing on Mars is really really hard. The atmosphere is thick enough that spacecraft will burn up if you aim directly for the surface, but it’s not thick enough to let you use parachutes to gently land on the surface.
Landing on the surface of Venus on the other hand, is super easy. The atmosphere is so thick that you can use parachutes no problem. If you can get on target and deploy a parachute capable of handling the terrible environment, your soft landing is pretty much assured. Surviving down there is another story, but we’ll get to that.
Venera 4 came next, launched on June 12, 1967. The Soviet scientists had few clues about what the surface of Venus was actually like. They didn’t know the atmospheric pressure, guessing it might be a little higher pressure than Earth, or maybe it was hundreds of times our pressure. It was tested with high temperatures, and brutal deceleration. They thought they’d built this thing plenty tough.
The Venera 4 spacecraft. Venera spacecraft 3 to 6 were similar. Image supplied by NASA
Venera 4 arrived at Venus on October 18, 1967, and tried to survive a landing. Temperatures on its heat shield were clocked at 11,000 C, and it experienced 300 Gs of deceleration.
The initial temperature 52 km was a nice 33C, but then as it descended down towards the surface, temperatures increased to 262 C. And then, they lost contact with the probe, killed dead by the horrible temperature.
We can assume it landed, though, and for the first time, scientists caught a glimpse of just how bad it is down there on the surface of Venus.
Venera 5 was launched on January 5, 1969, and was built tougher, learning from the lessons of Venera 4. It also made it into Venus’ atmosphere, returned some interested science about the planet and then died before it reached the surface.
Venera 6 followed, same deal. Built tougher, died in the atmosphere, returned some useful science.
Venera 7 was built with a full understanding of how bad it was down there on Venus. It launched on August 17, 1970, and arrived in December. It’s believed that the parachutes on the spacecraft only partially deployed, allowing it to descend more quickly through the Venusian atmosphere than originally planned. It smacked into the surface going about 16.5 m/s, but amazingly, it survived, and continued to send back a weak signal to Earth for about 23 minutes.
For the first time ever, a spacecraft had made it down to the surface of Venus and communicated its status. I’m sure it was just 23 minutes of robotic screaming, but still, progress. Scientists got their first accurate measurement of the temperatures, and pressure down there.
Bottom line, humans could never survive on the surface of Venus.
Venera 8 blasted off for Venus on March 17, 1972, and the Soviet engineers built it to survive the descent and landing as long as possible. It made it through the atmosphere, landed on the surface, and returned data for about 50 minutes. It didn’t have a camera, but it did have a light sensor, which told scientists being on Venus was kind of like Earth on an overcast day. Enough light to take pictures… next time.
The Venera 9 spacecraft. Image supplied by NASA
For their next missions, the Soviets went back to the drawing board and built entirely new landing craft. Built big, heavy and tough, designed to get to the surface of Venus and survive long enough to send back data and pictures.
Venera 9 was launched on June 8, 1975. It survived the atmospheric descent and landed on the surface of Venus. The lander was built like a liquid cooled reverse insulated pressure vessel, using circulating fluid to keep the electronics cooled as long as possible. In this case, that was 53 minutes. Venera 9 measured clouds of acid, bromine and other toxic chemicals, and sent back grainy black and white television pictures from the surface of Venus.
In fact, these were the first pictures ever taken from the surface of another planet.
Images from Venera 9 (top) and Venera 10 (bottom). Public Domain Images, courtesy of NASA/National Space Science Data Center.
Images from Venera 9 (top) and Venera 10 (bottom). Public Domain Images, courtesy of NASA/National Space Science Data Center.
Venera 10 lasted for 65 minutes and took pictures of the surface with one camera. The lens cap on a second camera didn’t release. The spacecraft saw lava rocks with layers of other rocks in between. Similar environments that you might see here on Earth.
Venera 11 was launched on September 9, 1975 and lasted for 95 minutes on the surface of Venus. In addition to confirming the horrible environment discovered by the other landers, Venera 11 detected lightning strikes in the vicinity. It was equipped with a color camera, but again, the lens cap failed to deploy for it or the black and white camera. So it failed to send any pictures home.
Venera 12 was launched on September 14, 1978, and made it down to the surface of Venus. It lasted 110 minutes and returned detailed information about the chemical composition of the atmosphere. Unfortunately, both its camera lens caps failed to deploy, so no pictures were returned. And pictures are what we really care about, right?
Venera 13 was built on the same tougher, beefier design, and was blasted off to Venus on October 30, 1981, and this one was a tremendous success. It landed on Venus and survived for 127 minutes. It took pictures of its surroundings using two cameras peering through quartz windows, and saw a landscape of bedrock. It used spring-loaded arms to test out how compressible the soil was.
The surface of Venus as captured by Soviet Venera 13 lander in March of 1982. NASA/courtesy of nasaimages.org
Venera 14 was identical and launched just 5 days after Venera 13. It also landed and survived for 57 minutes. Unfortunately, its experiment to test the compressibility of the soil was a botch because one of its lens caps landed right under its spring-loaded arm. But apart from that, it sent back color pictures of the hellish landscape.
And with that, the Soviet Venus landing program ended. And since then, no additional spacecraft have ever returned to the surface of Venus.
It’s one thing for a lander to make it to the surface of Venus, last a few minutes and then die from the horrible environment. What we really want is some kind of rover, like Curiosity, which would last on the surface of Venus for weeks, months or even years and do more science.
And computers don’t like this kind of heat. Go ahead, put your computer in the oven and set it to 850. Oh, your oven doesn’t go to 850, that’s fine, because it would be insane. Seriously, don’t do that, it would be bad.
Engineers at NASA’s Glenn Research Center have developed a new kind of electrical circuitry that might be able to handle those kinds of temperatures. Their new circuits were tested in the Glenn Extreme Environments Rig, which can simulate the surface of Venus. It can mimic the temperature, pressure and even the chemistry of Venus’ atmosphere.
A before (top) and after (bottom) image of the electronics after being tested in the Glenn Extreme Environments Rig. Credit: NASA
The circuitry, originally designed for hot jet engines, lasted for 521 hours, functioning perfectly. If all goes well, future Venus rovers could be developed to survive on the surface of Venus without needing the complex and short lived cooling systems.
This discovery might unleash a whole new era of exploration of Venus, to confirm once and for all that it really does suck.
While the Soviets had a tough time with Mars, they really nailed it with Venus. You can see how they built and launched spacecraft after spacecraft, sticking with this challenge until they got the pictures and data they were looking for. I really think this series is one of the triumphs of robotic space exploration, and I look forward to future mission concepts to pick up where the Soviets left off.
Are you excited about the prospects of exploring Venus with rovers? Let me know your thoughts in the comments
Forgot to include the link to the above post: https://www.universetoday.com/134338...surface-venus/.
Phantastic link, DW! Personally I am still sceptic about men ever being able to live on Venus on account of the heat of the planet. You see I live in a city where the spring/summer temperatures reach 36°.
NASA's exploration strategy has undergone a quiet revolution, with the emphasis shifting to exploring the planets in more detail. Dawn is in permanent orbit round Ceres, so it has become an artificial moon of that planet. See https://www.universetoday.com/135585...s-takes-video/. Jupiter has another going round, called Juno. Saturn with its many moons and rings has a probe, Cassini, making dives through the rings and taking images of Saturn's moons. It will be crashed into Saturn when its finished its tasks. Mars has several land-based exploration vehicles on that planet.
There is growing interest in finding life on our nearest neighbour exoplanets in their so-called "habitable zone". I don't think they will find advanced forms of life th4re but single-cell life, perhaps.
Universetoday.com is now my main source of information. Its an excellent website for info on exploring the universe.
Yes, I noticed the shift too. These programs all must be very expensive. It seems that they are very anxious to unload humans somewhere else. I see a certain analogy with the discovery of America.
I´ll have a look at universe today. There seem to be two or three serious astronomic sites.
Yes, they are expensive, but of special interest is a return visit to Pluto, way out in the Kuiper Belt. The first visit was a flyby, just to get some info on this planet. The results were so interesting that NASA is planning to return, hopefully for a longer visit.
Interesting news, DW, I´ll have a look later on if there are any news about it.
I didn't realize there were so many Venera missions. Putting a rover on Venus does provide a challenge that is worth solving. There should be a way to terraform Venus and Mars and keep Earth from becoming like Venus when it gets closer to the Sun although I know we aren't likely to find a way to do all of that for thousands of years.
This is just a joke but I found it interesting because some of these concerns might become serious in a not so far future:
https://blog.nols.edu/2017/04/01/new...el-april-fools
Some images of Pluto and its surroundings:
http://astro.wsu.edu/worthey/astro/html/lec-pluto.html
"One of the most prominent features on Pluto is the informally named Cthulhu Regio, also called "the whale," which stretches across 1,900 miles (3,000 km). Cthulhu Regio is pockmarked with craters, which suggests it is billions of years old — much older than the craterless, young "heart" it borders. Scientists have said the dark region's reddish coloring might come from tholins, which are complex hydrocarbons.
To further investigate how the whale got its coloring, Yasuhito Sekine, an associate professor at the University of Tokyo, conducted heating experiments on organic molecules, like formaldehyde, that would have been present on the newly forming Pluto soon after the formation of the solar system. Sekine found that he could produce the same dark, reddish color after heating solutions above 122 degrees Fahrenheit (50 degrees Celsius) for several months. "
http://www.space.com/36853-pluto-wha...on-impact.html
More moons are being discovered in the Kuiper Belt. This one is 600 miles across, see EarthSky:
http://earthsky.org/space/hubble-moo...anet-2007-or10
EarthSky and Space.com are the two websites I have been following for some years now, https://www.universetoday.com is more recent, I get updates most days.
A long article on how difficult it would be to send an unmanned mission at 20% of the speed of light to Alpha Centauri, the nearest star to the solar system.
http://earthsky.org/space/alpha-centauri-travel-time