NASA Verdict: Most Exoplanets Are Not Habitable

Superflares from the majority of stars would likely sterilize any planet in its “habitable zone.”

You don’t want to enter a HAZMAT zone. That’s where toxic materials pose a danger to life or the environment. NASA took on this word for a program called HAZMAT, standing for “Habitable Zones and M dwarf Activity across Time.” An article for NASA Exoplanet Exploration announces one of the first findings from HAZMAT: “Superflares from young red dwarf stars imperil planets.” That’s because their parent stars, the most numerous in the universe (M-dwarf stars), are nasty.

“M dwarf” is the astronomical term for a red dwarf star — the smallest, most abundant and longest-lived type of star in our galaxy. The HAZMAT program is an ultraviolet survey of red dwarfs at three different ages: young, intermediate, and old.

Stellar flares from red dwarfs are particularly bright in ultraviolet wavelengths, compared with Sun-like stars. Hubble’s ultraviolet sensitivity makes the telescope very valuable for observing these flares. The flares are believed to be powered by intense magnetic fields that get tangled by the roiling motions of the stellar atmosphere. When the tangling gets too intense, the fields break and reconnect, unleashing tremendous amounts of energy.

M-Dwarf stars emit deadly flares that can strip away a planet’s atmosphere and sterilize its surface. Credits: NASA, ESA and D. Player (STScI).

The team has found that the flares from the youngest red dwarfs they surveyed — just about 40 million years old — are 100 to 1,000 times more energetic than when the stars are older. This younger age is when terrestrial planets are forming around their stars.

The statements about age and evolution are heavily laden by theories about stellar and planetary evolution, but the observations are empirical. Violent outbursts from red dwarfs were seen by the Hubble Space Telescope. How many stars fit this classification?

Approximately three-quarters of the stars in our galaxy are red dwarfs. Most of the galaxy’s “habitable-zone” planets — planets orbiting their stars at a distance where temperatures are moderate enough for liquid water to exist on their surface — likely orbit red dwarfs. In fact, the nearest star to our Sun, a red dwarf named Proxima Centauri, has an Earth-size planet in its habitable zone.

However, young red dwarfs are active stars, producing ultraviolet flares that blast out so much energy that they could influence atmospheric chemistry and possibly strip off the atmospheres of these fledgling planets.

Our sun and atmosphere cooperate to foster life. Credit: Illustra Media.

Compared to these active stars, our sun is an extremely stable and quiet star (see 7 March 2007 and ICR). What would happen to a precocious molecule trying to become a replicator to kickstart life on a planet in the habitable zone of a red dwarf?

The observing program detected one of the most intense stellar flares ever observed in ultraviolet light. Dubbed the “Hazflare,” this event was more energetic than the most powerful flare from our Sun ever recorded.

“With the Sun, we have a hundred years of good observations,” Loyd said. “And in that time, we’ve seen one, maybe two, flares that have an energy approaching that of the Hazflare. In a little less than a day’s worth of Hubble observations of these young stars, we caught the Hazflare, which means that we’re looking at superflares happening every day or even a few times a day.“

The scientists don’t want to look pessimistic about the chances for life on such planets, because SETI and astrobiology depend on the possibility of life “emerging” by unguided natural processes.

Could super-flares of such frequency and intensity bathe young planets in so much ultraviolet radiation that they forever doom chances of habitability? According to Loyd, “Flares like we observed have the capacity to strip away the atmosphere from a planet. But that doesn’t necessarily mean doom and gloom for life on the planet. It just might be different life than we imagine. Or there might be other processes that could replenish the atmosphere of the planet. It’s certainly a harsh environment, but I would hesitate to say that it is a sterile environment.”

Hot blue stars are similarly inhospitable to life.

Surely, though, it’s hard to “imagine” circumstances where such violent radiation could assist life, even if one accepts the possibility of the origin of life by natural causes. Appeals to imagination or unobserved “other processes” seem like acts of desperation to escape the obvious: only a minority of stars can support habitable planets. At the other extreme, giant stars cause similar problems, exuding copious amounts of damaging radiation.

Scoring Points for Intelligent Design

In his new book Children of the Light: Astonishing Properties of Sunlight that Make Us Possible, Dr Michael Denton describes numerous aspects of sunlight that benefit life. These aspects, furthermore, seem tailored for human life.

The precisely tuned partnership of photosynthesis — feeding plants and manufacturing oxygen as a waste product — with the radiation of the Sun, with the nature of Earth’s atmosphere is too convenient to accommodate an explanation depending on blind chance alone.

A short video trailer posted by Evolution News & Science Today gives just a brief introduction to the many “coincidences” between the Sun, the Earth, and Earth’s atmosphere that make life flourish on the only planet we know that has any form of life. Enough coincidences support a design inference. If life could not exist without a “conspiracy” of multiple independent factors, belief in “blind chance alone” becomes strained.

Scoring Points for Creation

Moreover, the factors required for habitability are so numerous as to point beyond intelligent design. The Bible says that God “made the earth to be inhabited” (Isaiah 45:18). It would be expected, therefore, that an Almighty God who revealed His purposes to His creatures and treats them with everlasting lovingkindness (Psalm 136) would be “clearly seen” in the “things that are made” (Psalm 19:1-6, Romans 1:18-23). The evidence would be strong enough to render any doubter “without excuse” for refusing to see His divine nature through observation of His creation.

In a new article at CMI, Dr Henry Richter shares once again the calculations he gave in his book Spacecraft Earth: A Guide for Passengers that argue we are alone in the universe. He made similar arguments here at CEH on another occasion (11 August 2017). Richter concludes with confidence that the intelligent designer is none other than the God of the Bible.

I know a bit about planets. I worked in JPL/NASA from 1955 to 1960 in the field of space exploration. There are a lot of wishful thinkers out there who are pouring a lot of money into a search for life against all odds. They refuse to think this through because an underlying philosophy that time and chance (evolution) could produce it all. But this is nothing new. A wise man once said, “There is nothing new under the sun” (Ecclesiastes 1:9). Since the beginning of time, there has been and will always be people who are willingly ignorant of the evidence of a Creator all around us (Romans 1:20).