Scientists studied the atmospheres of two exoplanets, planets orbiting another star, earlier this year. Both planets are roughly Earth-sized, with atmospheres a bit like the Solar System’s terrestrial planets.
Juno arrived at Jupiter last month, and will start its science mission in October.
Finally, scientists found more than a thousand new planets; including more than a hundred Earth-sized ones.
- TRAPPIST-1 b and c
- Juno at Jupiter
- Kepler: More than 100 Earth-Sized Planets Discovered
As usual, I’ll start by talking about science, faith, and dealing with reality.
He may have been sincere, but I’m quite sure he’s wrong.
I could be a Christian, following our Lord, and believe that a solid dome kept the ‘ocean of heaven’ from flooding the earth I walk on.
I could even believe that a 17th century Calvinist was right about the universe being created on the nightfall preceding October 23, 4004 BC.
But ignoring what we’ve learned in the two dozen or so centuries since Mesopotamian culture provided poets with imagery we read in the Old testament is not vital to Christian belief.
I’m a Christian and a Catholic, so studying this wonder-filled universe and using what we learn to develop new tools is okay. Science and technology are part of being human. Ethics apply, of course. (Catechism of the Catholic Church, 2293–2295)
Besides, as I say rather often, scientific discoveries are invitations “to even greater admiration for the greatness of the Creator.” (Catechism, 283)
Studying this immense and ancient creation honestly and methodically cannot interfere with an informed faith, because “the things of the world and the things of faith derive from the same God.” (Catechism, 159)
This isn’t a particularly new idea.
Dominican friar and Catholic bishop Albertus Magnus, born around 1200, is now patron saint of scientists, students, medical technicians, philosophers, and the natural sciences.
Catholic bishop and scientist Nicolas Steno helped launch paleontology as a science in 1669.
And the Pontifical Academy of Sciences hosted a “Study Week on Astrobiology” in November of 2009.
Can’t say that I blame him. His newfangled ideas upset some folks who apparently had a shaky grasp of distinctions between poetry and science. European politics since 1517 didn’t help, and that’s another topic.
(From NASA/JPL-CalTech/R. Hurt, used w/o permission.)
(Comparison of the Kepler-186, Kepler-452, and Solar planetary systems. The green area in each is the star’s habitable zone, where liquid water could exist on an Earth-like planet.)
It’s been a year since “Earth 2.0,” Kepler-452b, was in the news. One of the first “Earth 2.0” op-ed pieces I saw was by scientist and former White House Senior Policy Analyst, Jeff Schweitzer.
He has a Ph.D. in marine biology/neurophysiology, probably knows his field very well, and made some all-too-familiar assumptions about Christianity:
“Earth 2.0: Bad News for God”
Jeff Schweitzer, Huffington Post (July 23, 2015)
“…Let us be clear that the Bible is unambiguous about creation: the earth is the center of the universe, only humans were made in the image of god, and all life was created in six days. All life in all the heavens. In six days….”
Some Christians apparently agree with Dr. Schweitzer — that Christianity depends on believing one of the Genesis creation narratives is word-for-word true, from the viewpoint of a contemporary Western literalist.
I don’t see it that way, but I figure that part of my job is appreciating God’s handiwork: not insisting that ancient Mesopotamians were spot-on accurate.
Even if I didn’t approve of the way reality works, it’s not my decision:
“Our God is in heaven; whatever God wills is done.”
“First atmospheric study of Earth-sized exoplanets reveals rocky worlds”
Jennifer Chu, MIT News (July 20, 2016)
“Two potentially habitable planets in nearby system are confirmed to be rocky.
“On May 2, scientists from MIT, the University of Liège, and elsewhere announced they had discovered a planetary system, a mere 40 light years from Earth, that hosts three potentially habitable, Earth-sized worlds. Judging from the size and temperature of the planets, the researchers determined that regions of each planet may be suitable for life.
“Now, in a paper published today in Nature, that same group reports that the two innermost planets in the system are primarily rocky, unlike gas giants such as Jupiter. The findings further strengthen the case that these planets may indeed be habitable. The researchers also determined that the atmospheres of both planets are likely not large and diffuse, like that of the Jupiter, but instead compact, similar to the atmospheres of Earth, Venus, and Mars….”
True enough, Earth, Venus, and Mars have atmospheres that stick pretty close to the planet; but those atmospheres are very different.
The atmospheres of Venus and Mars are mostly carbon dioxide — but Venus is hot, 740 K/467 °C/872 °F at the surface, with air pressure 93 times Earth’s. Martian surface pressure is only about 6% Earth’s, and cold enough for carbon dioxide frost in winter.
Earth’s atmosphere is mostly nitrogen and oxygen, and it’s the only ‘habitable’ planet of the trio.
They’re almost certainly tidally locked to the star, one side in constant sunlight, with years roughly 1.5 and 2.5 Earth days long. That close to TRAPPIST-1, the star’s ‘wind’ probably blew away whatever water they started with.
Refined orbital data and calculations, finished only two weeks before the double transit, didn’t give the researchers much time to coordinate with the Hubble team.
“…’We thought, maybe we could see if people at Hubble would give us time to do this observation, so we wrote the proposal in less than 24 hours, sent it out, and it was reviewed immediately,’ [MIT’s Julien] de Wit recalls. ‘Now for the first time we have spectroscopic observations of a double transit, which allows us to get insight on the atmosphere of both planets at the same time.’
“Using Hubble, the team recorded a combined transmission spectrum of TRAPPIST-1b and c, meaning that as first one planet then the other crossed in front of the star, they were able to measure the changes in wavelength as the amount of starlight dipped with each transit….”
(Jennifer Chu, MIT News)
The “artist’s depiction” and that NASA/ESA/STScl animation make TRAPPIST-1 look a whole lot redder than it would seem to someone close enough to see the star as a “sun.”
- “NASA’s Hubble Telescope Makes First Atmospheric Study of Earth-Sized Exoplanets”
NASA press release (July 20, 2016)
- “A combined transmission spectrum of the Earth-sized exoplanets TRAPPIST-1 b and c”
Julien de Wit, Hannah R. Wakeford, Michaël Gillon, Nikole K. Lewis, Jeff A. Valenti, Brice-Olivier Demory, Adam J. Burgasser, Artem Burdanov, Laetitia Delrez, Emmanuël Jehin, Susan M. Lederer, Didier Queloz, Amaury H. M. J. Triaud & Valérie Van Grootel; Letter, Nature (Received May 18, 2016; Accepted June 4, 2016; Published online July 20, 2016)
- “Temperate Earth-sized planets transiting a nearby ultracool dwarf star”
Michaël Gillon, Emmanuël Jehin, Susan M. Lederer, Laetitia Delrez, Julien de Wit, Artem Burdanov, Valérie Van Grootel, Adam J. Burgasser, Amaury H. M. J. Triaud, Cyrielle Opitom, Brice-Olivier Demory, Devendra K. Sahu, Daniella Bardalez Gagliuffi, Pierre Magain & Didier Queloz; Letter, Nature (May 12, 2016)
- “Three Potentially Habitable Worlds Found Around Nearby Ultracool Dwarf Star”
ESO (European Southern Observatory) press release (May 2, 2016)
“Juno probe enters into orbit around Jupiter”
Jonathan Amos, BBC News (June 5, 2016)
“The US space agency has successfully put a new probe in orbit around Jupiter.
“The Juno satellite, which left Earth five years ago, had to fire a rocket engine to slow its approach to the planet and get caught by its gravity.
“A sequence of tones transmitted from the spacecraft confirmed the braking manoeuvre had gone as planned….
“…Tuesday’s orbit insertion has put Juno in a large ellipse around the planet that takes just over 53 days to complete.
“A second burn of the rocket engine in mid-October will tighten this orbit to just 14 days. It is then that the science can really start….”
Data from Juno’s instruments should tell scientists how much of Jupiter is water, and help them map the planet’s magnetic and gravitational fields. That will help sort out theories of how Jupiter, and the Solar System, formed; and what powers its magnetic field.
Another science goal is measuring orbital frame-dragging around Jupiter. Frame-dragging is what happens when moving concentrations of mass-energy drag space-time along with them. It’s also called Lense-Thirring precession, and there will not be a test on this.
Data from Gravity Probe B, in Earth orbit, confirmed that frame dragging happens — after heavy-duty statistical analysis. The phenomenon should be easier to measure near Jupiter, since the planet has 317.8 times Earth’s mass and spins more than twice as fast.
“Juno Armored Up to Go to Jupiter”
NASA/JPL (July 12, 2010)
“…’Juno is basically an armored tank going to Jupiter,’ said Scott Bolton, Juno’s principal investigator, based at Southwest Research Institute in San Antonio. ‘Without its protective shield, or radiation vault, Juno’s brain would get fried on the very first pass near Jupiter.’…”
Jupiter’s intense magnetic field is much stronger than Earth’s, trapping and accelerating charged particles, forming a doughnut of radiation like Earth’s Van Allen radiation belt; but a whole lot stronger.
Juno‘s path avoids the worst of the radiation, and much of the spacecraft’s sensitive electronics are inside a titanium “radiation vault” with one-centimeter-thick walls.
That should keep the spacecraft working for all 37 planned 14-day ‘science’ orbits. Some of the instruments may not last that long.
After the 37th orbit, Juno is supposed to start a controlled deorbit; a five-and-a-half day maneuver that drops it into Jupiter’s atmosphere — following NASA’s planetary protection policy. Jupiter almost certainly doesn’t support life of our variety, but one of its moons is another matter.
One of the simpler explanations for Europa‘s smooth surface is that the Jovian moon has a large ocean under its icy crust.
If that’s the case, we might find critters living in that ocean. Meanwhile, NASA wants to be sure than any critters on Jupiter’s moons grew there — and aren’t survivors from a crashed spaceship. And that’s yet another topic.
- Juno (spacecraft)
- Juno mission
Southwest Research Institute
- “Juno Armored Up to Go to Jupiter”
NASA/JPL press release (July 12, 2010)
“Kepler telescope discovers 100 Earth-sized planets”
Paul Rincon, BBC News (May 10, 2016)
“Nasa’s Kepler telescope has discovered more than 100 Earth-sized planets orbiting alien stars.
“It has also detected nine small planets within so-called habitable zones, where conditions are favourable for liquid water – and potentially life.
“The finds are contained within a catalogue of 1,284 new planets detected by Kepler – which more than doubles the previous tally….”
As of this week, we’ve found 3,472 planets orbiting 2,597 other stars; 589 of them have more than one known planet. That’s enough to make some educated guesses about planets we haven’t spotted yet.
Scientists figure about one in five sun-like stars have at least one ‘Earth-like’ planet — a planet that’s between one and two times Earth’s diameter — in the habitable zone.1
That seems reasonable, since the Solar System very nearly has two: Earth, and Venus. Granted, Venus is 94.99% Earth’s diameter, and at the inside edge of Sol’s habitable zone.
Assuming 200,000,000,000 stars in our galaxy, that gives us 11,000,000,000 ‘habitable’ planets: 40,000,000,000, if we add red dwarf stars to the mix. That’s a lot of planets, and the nearest one may be within 12 light years of us.
So where is everybody?
First of all, there’s a big difference between (potentially) ‘habitable’ and ‘inhabited.’
The only place in that list that we know has life is Earth. Venus almost certainly is lifeless, Mars might have enough water left to keep microorganisms going, and the rest — we simply don’t know yet.
The rest of the universe may be ‘more of the same,’ or we may learn that life got started on billions of worlds. We may even hit the jackpot, and meet folks who are as chatty as we are. And that’s yet again another topic.
- The Extrasolar Planet Catalog
The Extrasolar Planets Encyclopaedia; Exoplanet Team
- Habitable Exoplanets Cataolg
University of Puerto Rico at Arecibo
European Southern Observatory
Ames Research Center
- New Worlds Atlas
- “Prevalence of Earth-size planets orbiting Sun-like stars”
Erik A. Petigura, Andrew W. Howard, Geoffrey W. Marcy; abstract; Cornell University Library (Submitted November 26,2013)
- “Astronomers answer key question: How common are habitable planets?”
Robert Sanders, Berkeley News (November 4, 2013)
1 A star’s habitable zone, or circumstellar habitable zone, is the volume surrounding a star where a planet like Earth isn’t baked to a crisp, like Mercury, or frozen, like the Solar System’s outer planets.