....Pluto- NASA / Unsplash Posted on 04/25/2023 9:49:45 AM PDT by Red Badger
....Pluto- NASA / Unsplash
Finding life on other planets might well be the holy grail of astronomy, but the hunt for suitable host planets that can sustain life is a resource-intensive task.
The search for exoplanets (planets outside our Solar System) involves competing for time on Earth’s biggest telescopes – yet the hit rate of this search can be disappointingly low.
In a new study published in Science, I and my international team of colleagues have combined different search techniques to discover a new giant planet. It could change the way we try to image planets in the future.
Imaging planets is no small feat
To satisfy our curiosity about our place in the universe, astronomers have developed many techniques to search for planets orbiting other stars. Perhaps the simplest of these is called direct imaging. But it’s not easy.
Direct imaging involves attaching a powerful camera to a large telescope and trying to detect light emitted, or reflected, from a planet. Stars are bright, and planets are dim, so it’s akin to searching for fireflies dancing around a spotlight.
It’s no surprise only about 20 planets have been found with this technique to date.
Yet direct imaging is of great value. It helps shed light on a planet’s atmospheric properties, such as its temperature and composition, in a way other detection techniques can’t.
HIP99770b: a new gas giant
Our direct imaging of a new planet, named HIP99770b, reveals a hot, giant and moderately cloudy planet. It orbits its star at a distance that falls somewhere between the orbital distances of Saturn and Uranus around our Sun.
With about 15 times the mass of Jupiter, HIP99770b is a real giant. However, it’s also more than 1,000℃, so it’s not a good prospect for a habitable world.
What the HIP99770 system does offer is an analogy to our own Solar System. It has a cold “debris disk” of ice and rock far out from the star, akin to a scaled-up version of the Kuiper Belt in our Solar System.
The main difference is that the HIP99770 system is dominated by one high-mass planet, rather than several smaller ones.
Searching with the light on
We reached our findings by first detecting hints of a planet via indirect detection methods. We noticed the star was wobbling in space, which hinted at the presence of a planet in the vicinity with a large gravitational pull.
This motivated our direct imaging efforts; we were no longer searching in the dark.
The extra data came from the European Space Agency’s Gaia spacecraft, which has been measuring the positions of nearly one billion stars since 2014. Gaia is sensitive enough to detect tiny variations of a star’s motion through space, such as those caused by planets.
We also supplemented these data with measurements from Gaia’s predecessor, Hipparcos. In total, we had 25 years’ worth of “astrometric” (positional) data to work with.
Previously, researchers have used indirect methods to guide imaging that has discovered companion stars, but not planets.
It’s not their fault: massive stars such as HIP99770 – which is almost twice the mass of our Sun – are reluctant to give up their secrets. Otherwise-successful search techniques can rarely reach the levels of precision required to detect planets around such massive stars.
Our detection, which used both direct imaging and astrometry, demonstrates a more efficient way to search for planets. It’s the first time the direct detection of an exoplanet has been guided through initial indirect detection methods.
Gaia is expected to continue observing until at least 2025, and its archive will remain useful for decades to come.
Mysteries remain
Astrometry of HIP99770 suggests it belongs to the Argus association of stars – a group of stars that moves together through space. This would suggest the system is rather young, about 40 million years old. That would make it roughly one-hundredth of the age of our Solar System.
However, our analysis of the star’s pulsations, as well as models of the planet’s brightness, suggest an older age of between 120 million and 200 million years. If this is the case, HIP99770 might just be an interloper in the Argus group.
Now that it’s known to host a planet, astronomers will aim to further unravel the mysteries of HIP99770 and its immediate environment.
Not only radio waves, but we sent a gold plated disk with our exact location and engraved pictures of our naked women.
Protestant, or atheist?
Or both.
Huh Huh...Huh Huh!
Wait, what?
What if the odds are way less than 1 out of a trillion? Look at each of these properties that have to be juuussst right that I can think of off the top of my head. Imagine the odds of each one being one out of a 1,000 (a few 0's). Multiply it out and it's 1 out of 10^36. And that's just the properties I can think of that are special about our planet, star, and galaxy. I'm sure there are many, many more properties that have to be fine-tuned to be just right for advanced life. And with my example I assumed the odds for each property was 1 out of 1,000, but I'd bet for most of them it's a lot less.
1. Planet just happens to be in the "goldilocks zone" for liquid water.
2. Planet in the right age of its life cycle for advanced life, while the host star also just happens to be the right age in its life cycle.
3. Planet has a molten core.
4. Planet has a big brother bodyguard planet like Earth has Jupiter, and the big planet is close enough to absorb most of the asteroids into its larger gravity well (sparing Earth from frequent ELA's), but far enough away so that the big planet doesn't cause too much tectonic activity on the life hosting planet.
5. Host star is near enough to other stars for the necessary cosmic radiation, but not too close and being too bombarded with cosmic radiation.
6. Planet's rotational axis wobbles some to give us some tectonic activity (to stir up necessary heavy elements to the surface), but not too much wobble.
7. Planet's orbit around host star is elliptic enough to help with tectonic activity but not too elliptic.
8. The planet have an accompanying moon just the right size and nearly circular orbit to provide a stabilizing effect on the planet's rotational axis. (Some say our Earth's rotational axis would vary as much as 90° without the moon.) Plus the moon also acts as a sentry like Jupiter does, absorbing asteroids.
9. The host star's iron enrichment be just enough to form planets, but not too rich.
10. The host star's orbit within its galaxy be circular enough.
11. The host galaxy absorb enough dwarf galaxies at a frequent enough rate to maintain its spiral state, but not too frequent. The fact that it's been probably 10 billion years since our Milky Way Galaxy absorbed a dwarf galaxy makes our galaxy somewhat fine-tuned for life in a way that most galaxies aren't.
12. The host star's distance from its galaxy center can't be too close (the massive red stars near the center of the galaxy would disrupt too many things on the planet), not can it be too far away (where there are less elements). It must be within the galactic disc, but not too close to the galactic center.
IMHO I guess it's possible that advanced life is out there somewhere. But only if God created it like He created Earth. Us Christians don't gain or lose anything whether or not we discover advanced life elsewhere. The atheists have to discover advanced life elsewhere to avoid admitting that Earth was especially fine-tuned for life. As for me, I'm not religious enough to believe in this much random chance.
That’s a good list, but we don’t even know if those are critical requirements or just a small subset of a much larger list. Our sun is also a very stable star in comparison to most, probably because of its slow rate of spin. Also, there have been several near-complete extinction events in earth’s past, so what are the odds that life has survived this long? We don’t know. A lot of extrasolar systems that we see have planets with unstable orbits that drift over time, but ours seems to be in an unusual resonance state involving all of them. What are the odds? We don’t know. The only way we’ll know what the odds are for life on other planets is to actually find life on other planets. And even if, incredibly, Earth is the only planet in the whole universe with life, does it matter? It’s a lot of wasted space, but God can waste all the space he wants. He’s God.
I think like Ross in believing that the universe's vastness is part of the design. https://reasons.org/explore/publications/questions-from-social-media/does-the-universe-s-immensity-imply-a-huge-waste.
No, I figured out the typo. It's the internet, we all should get a pass on that.
Was trying to understand your other claim, which you spell out above. But that's confusing. Google tells me that "lithosphere" is defined as the rocky outer layers of the Earth's crust, I guess as distinguished from the more liquid-y core and plastic mantle. So you're saying that stars and gas giant planets have a similar structure? Or just that any heavy elements that get incorporated into a star or planet would logically sink to the bottom, so to speak? Haven't heard this idea before.
How does the conventional model of these objects violate the laws of thermodynamics?
A real theist would not pronouncement on what can or can’t be in God’s infinity.
You are just small minded
Huh?!
Why does the primary star of a life-bearing planet need to be in the proximity of other stars!? Why the heck should that primary star and/or the life-bearing planet need "cosmic radiation?!"
(If you're saying that some minimal amount of mutation-inducing radiation is necessary for evolution to take place - and that has NOT been established as a prerequisite - then the primary star, itself, could provide it.)
Regards,
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atheist
Your post has almost as many assumptions as there are galaxies in the cosmos.
It is not a sign of intelligence to make up a bunch of rules that “intelligent life” must follow.
You're going to have to slow down for me here...how does this idea of metallic hydrogen affect the idea of a rocky stellar interior? Isn't the idea that hydrogen only becomes "metallic" (whatever that means...sounds weird) when confined under great pressure.
Thanks for the links btw, lots of cool stuff!
You and I believe the same thing, though I didn't state it clearly. My point is that people who believe that God doesn't exist and that we came to existence through a bunch of freak accidents (including the very planet we live on being here by accident) depend on a bunch of things that have to happen to be just right for the "accident" to happen correctly. One of those things is the presence of substances that our planet and sun were formed from (if it happened accidentally).
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