[1] - https://exoplanets.nasa.gov/exoplanet-catalog/8921/toi-715-b...

(Stellar, one could say.)

The guided tours are interesting. I've mentioned this before, but I am very jealous of this kind of content available for school kids. We had the slide shows with a tape recording with the unforgettable tone to signal to switch to the next slide. We had crappy VHS copies instead of the 8mm film projector, but I'm not sure it was an improvement. All of this interactive material is just so much more immersive.

Cycles of fire

There's plenty of others where you can zoom in/out of the solar system to see the modeled view of the Oort cloud and get a sense of scale interactively of Sol's influence. There's also the interactive image viewers of Hubble and JWST data so we can see the differences between visible/IR spectrum. There are plenty of others as well. Oh, and the fact you can access so much of the raw data to make your own visualizations as you like.

Overall, I think my tax dollars are performing nicely for my interests.

And for the future scientists and engineers who get exposed to this at an early age!

Edit: 1) proximity also leads these planets to be tidally locked, which some argue is not conducive to habitability, though I don't find that especially compelling.

2) The local EM environment and solar flares would not preclude sub-surface habitability, but that is true for planets outside of what we consider the habitable zone as well. e.g. life on Europa has been hypothesized, but it is FAR outside the suns habitable zone.

I don't think anyone will be leaving that atmosphere with chemical propulsion any time soon...

Gravity on surface of this planet will be 3(times heavier than earth)/(1.55(radius)^2), so 1.25g, however escape velocity also depends on planet radius so we get sqrt(1.55 * 1.25) = 1.4 earths escape velocity (so 15.7km/s). Assuming Isp specific impulse of engine of around 300s, let's compute m0/mf (initial mass of rocket / payload) = exp(vEsc/(Isp*g0)) (g0=9.8m/s^2 (on both planets)):

For earth, it's 45.

For this planet, it's 208.

So, the rocket (using our current chemical engine technology) needs 4.6 times more fuel than on earth. Much more difficult, but maybe possible...

edit: formatting

Plus, if it would take something like a Saturn V just to put the mass of a potato into low orbit I could easily envision an extraterrestrial civilization thinking it wasn’t worth the cost to try.

That's why it doesn't really help much to launch rockets from a balloon -- getting there is not a problem.

I'm sure that's true holding all else the same, but all else isn't the same.

Maybe it's airless due to stronger stellar winds.

>>>ts mass is 3.02 Earths, it takes 19.3 days to complete one orbit of its star, and is 0.083 AU from its star. Its discovery was announced in 2023

https://i.imgur.com/ghLnFrH.png

--

What would gravity be on that thing, it doesnt say what its circadian rhythm is.. so how long is a day, if a "year" is 19 earth days (or is the period in 'day' local-solar-system-days?)

It'd be pretty messy to instead define things in the database in object relative terms, particularly when you usually know things like the orbital period with significantly more accuracy than rotational velocity.

Thanks, though - I wasn’t sure if we always use a local reference but then au is as local a unit as possible at these scales.

TOI-715 b has a log g value of 5.0 +/- 0.2. Earth is 2.992.

https://www.jpl.nasa.gov/galleries/visions-of-the-future

I've always been more partial to exoplanet.eu though: https://exoplanet.eu/catalog/toi_715_b--8668/. It's not quite as prettied up but it's usually more practical in presentation.

Europa is quite probably 'habitable'.

Also, our earth did propably produce complex life so well because of the moon stabilizing earths rotation and allowing more or less stable climate.

The mass ratio of moon/earth is comparably larger then other satellite systems, which, encorporated into the model of habitable zones, would make them much less common.

Also, jupiter has a significant role in shielding earth from asteriods. Another aspect of stability.

I agree, habitable zone is way more than just distance to star or enough gravity for an atmosphere and liquid water.

Well, for some threshold of "easy" I guess.

"Orbital Cousins to Earth" OCEs. Find the # of OCEs, and maybe we have finer granulation, Second Cousins have an atmosphere, Step-sisters have water and an OnlyPlanets account... (which seems to be making the rounds at Nasa)

(I may have played too much Factorio)

I guess you’d also have to build it in interstellar space to avoid planets and asteroids.

FTL means we actually get to see the grandeur of the universe instead of hypothesizing mathematical models of it. Without FTL, we'll never leave this star system. The grandeur of the universe will be nothing but our imagination, instead of a real thing you can see with your own eyes.

Human existence doesn’t scale to inter-star system travel.

My money is on a quantum theory of gravity unlocking the ability to cheaply warp space.

If FTL were possible, causality breaks too. Plus if there's other life out there who have discovered FTL, we shouldn't even be here. Don't get your hopes up for more than a tiny portion of the universe ever being explorable.

Besides, that only applies to truly superluminal velocities, it doesn't hold for other forms of travel like wormholes or warp engines.

Sure, traveling at Voyager’s (impressive, but essentially wagon) speed won’t get it done. But betting against technological advancement has made fools of a vast many.

But the real problem with generation ships is not technological. Technology can't solve the fundamental social and psychological problems of locking some humans in a box for a hundred generations. That's the most important problem, and the one that's usually waved away with "oh you just can't imagine future technology"

They were intending to use the ship to get to the Tau Ceti system: https://exoplanets.nasa.gov/exoplanet-catalog/7179/tau-ceti-...

Mormonism seems well-suited for the religion role you mention since they have the concept of a particular planet being close to the residence of their god: https://en.m.wikipedia.org/wiki/Kolob

To go see it.

Why would the ability to visit other planets, and see them, suddenly negate the point of existence, since we can then go see it.

Like there is only a point if things can only be imagined, and not actually seen.

That would be like. "now that cars exists, and we can visit the Grand Canyon, suddenly there is no point of existence".

I wonder if I am missing anything - given it's in MNRAS already - or this is likely an artifact of auto-correction.

[1] https://ui.adsabs.harvard.edu/abs/2011AGUFM.P21C1675D/abstra...

Wiki ref check: https://en.wikipedia.org/wiki/Solar_irradiance

So it is a stretch for me to think there are even a few planets in the galaxy that could host human life as we know it.

EDIT: R⊕ appears to be something related to Earth. Perhaps a planetary radius?

It is domain-specific, so it should probably be changed in the title.

I will say that it is a very nice symbol - easy to write out by hand, makes for quick note-taking. Same for the symbol used for the sun (which isn't rendering for me, but is a circle with a dot in the middle).

https://en.wikipedia.org/wiki/Planet_symbols

https://en.wikipedia.org/wiki/Earth_radius

  "The domain-specific notation in this paper is inscrutable to me."

A tidal locked planet might still allow life in the twilight zones.

But since this one is orbiting close to a flare star, life might have other problems there

Surface gravity would be 38m/s² for a rocky planet (~390% earth's surface gravity) and 8.2m/s² for a water world (~84% earth's surface gravity). I'm not an astronomer so I don't know if anything in between those values is a realistic scenario, but I wonder how you got your 125% of earth's surface gravity.

Surface gravity? I just computed that. Color temp? Had to check the ole memory banks.

They should be doing stuff like computing how much of the sky this sun occupies, so you could get a sense of it, with the color. Is it tidally locked? Or at least does it fit the criteria?

The distance, eccentricity (which here leaves the distance a constant), and temperature of the associated star could be used to give some kind of insolation number, and from there a very casual steady-state blackbody temperature of the planet, which is a start and is better than nothing. At that point you can start looking up what gases would stay and which would go as kind of a maximum before you started thinking about stellar winds and the like.

If they would have no tilt then the seasons would be the same all over the planet unlike ours where they're opposite in each hemisphere.

* Astrometeorologists feel free to correct me on this.

  The relative increase in solar irradiation at closest approach to the Sun (perihelion) compared to the irradiation at the furthest distance (aphelion) is slightly larger than four times the eccentricity. For Earth's current orbital eccentricity, incoming solar radiation varies by about 6.8%, while the distance from the Sun currently varies by only 3.4% (5.1 million km or 3.2 million mi or 0.034 au).[9]

  Perihelion presently occurs around 3 January, while aphelion is around 4 July. When the orbit is at its most eccentric, the amount of solar radiation at perihelion will be about 23% more than at aphelion. However, the Earth's eccentricity is so small (at least at present) that the variation in solar irradiation is a minor factor in seasonal climate variation, compared to axial tilt and even compared to the relative ease of heating the larger land masses of the northern hemisphere.[10] 

This is like asking why should one try getting a better job while some people live in hunger.

Civilization has to work in many directions in order to progress. While some people are trying to find a way to deal with local issues (climate change, production, goverenance etc.) other people search a new potential home or a colony.

> Should this second planet be confirmed, it would represent the smallest habitable zone planet discovered by TESS to date.

In this context, we report on the discovery and validation of TOI-715 b, a planet orbiting its nearby (42 pc) M4 host (TOI-715/TIC 271971130) with a period d. TOI-715 b was first identified by TESS and validated using ground-based photometry, high-resolution imaging and statistical validation. The planet’s orbital period combined with the stellar effective temperature give this planet an installation , placing it within the most conservative definitions of the habitable zone for rocky planets.