Is Kepler-452b an Earth-like planet? Does it support life?

Apologetics and the progress of science
Apologetics and the progress of science

Previously, I blogged about a few of the minimum requirements that a planet must satisfy in order to support complex life.

Here they are:

  • a solar system with a single massive Sun than can serve as a long-lived, stable source of energy
  • a terrestrial planet (non-gaseous)
  • the planet must be the right distance from the sun in order to preserve liquid water at the surface – if it’s too close, the water is burnt off in a runaway greenhouse effect, if it’s too far, the water is permanently frozen in a runaway glaciation
  • the planet has to be far enough from the star to avoid tidal locking and solar flares
  • the solar system must be placed at the right place in the galaxy – not too near dangerous radiation, but close enough to other stars to be able to absorb heavy elements after neighboring stars die
  • a moon of sufficient mass to stabilize the tilt of the planet’s rotation
  • plate tectonics
  • an oxygen-rich atmosphere
  • a sweeper planet to deflect comets, etc.
  • planetary neighbors must have non-eccentric orbits
  • planet mass must be enough to retain an atmosphere, but not so massive to cause a greenhouse effect

Now what happens if we disregard all of those characteristics, and just classify an Earth-like planet as one which is the same size and receives the same amount of radiation from its star? Well, then you end up labeling a whole bunch of planets as “Earth-like” that really don’t permit life.

Here’s an article from The Conversation which talks about a recent case of science fiction trumping science facts. (H/T JoeCoder)


NASA’s announcement of the discovery of a new extrasolar planet has been met with a lot of excitement. But the truth is that it is impossible to judge whether it is similar to Earth with the few parameters we have – it might just as well resemble Venus, or something entirely different.

The planet, Kepler-452b, was detected by the Kepler telescope, which looks for small dips in a star’s brightness as planets pass across its surface. It is a method that measures the planet’s size, but not its mass. Conditions on Kepler-452b are therefore entirely estimated from just two data points: the planet’s size and the radiation it receives from its star.

Size and radiation from its star? That’s all?


Kepler-452b was found to be 60% larger than the Earth. It orbits a sun-like star once every 384.84 days. As a result, the planet receives a similar amount of radiation as we do from the sun; just 10% higher. This puts the Kepler-452b in the so-called “habitable zone”; a term that sounds excitingly promising for life, but is actually misleading.

The habitable zone is the region around a star where liquid water could exist on a suitable planet’s surface. The key word is “suitable”. A gas-planet like Neptune in the habitable zone would clearly not host oceans since it has no surface. The habitable zone is best considered as a way of narrowing down candidates for investigation in future missions.

What about plate tectonics – does it have that?

Kepler-452b’s radius puts it on the brink of the divide between a rocky planet and a small Neptune. In the research paper that announced the discovery, the authors put the probability of the planet having a rocky surface about 50%-60%, so it is by no means sure.

Rocky planets like the Earth are made from iron, silicon, magnesium and carbon. While these ingredients are expected to be similar in other planetary systems, their relative quantities may be quite different. Variations would produce alternative planet interiors with a completely different geology.

For example, a planet made mostly out of carbon could have mantles made of diamond, meaning they would not move easily. This would bring plate tectonics to a screeching halt. Similarly, magnesium-rich planets may have thick crusts that are resilient to fractures. Both results would limit volcano activity that is thought to be essential for sustaining a long lasting atmosphere.

What about retaining the right kind of atmosphere, which depends on the mass of the planet. Does it have that?

If Kepler-452b nevertheless has a similar composition to Earth, we run into another problem: gravity. Based on an Earth-like density, Kepler-452b would be five times more massive than our planet.

This would correspond to a stronger gravitational pull, capable of drawing in a thick atmosphere to create a potential runaway greenhouse effect, which means that the planet’s temperature continues to climb. This could be especially problematic as the increasing energy from its ageing sun is likely to be heating up the surface. Any water present on the planet’s surface would then boil away, leaving a super-Venus, rather than a super-Earth.

You might remember that “retain atmosphere” requirement from the lecture by Walter Bradley that I posted with a summary a few days ago.

What about having a Jupiter-sized sweeper planet – does it have that?

Another problem is that Kepler-452b is alone. As far as we know, there are no other planets in the same system. This is an issue because it was most likely our giant gas planets that helped direct water to Earth.

At our position from the sun, the dust grains that came together to form the Earth were too warm to contain ice. Instead, they produced a dry planet that later had its water most likely delivered by icy meteorites. These frozen seas formed in the colder outer solar system and were kicked towards Earth by Jupiter’s huge gravitational tug. No Jupiter analogue for Kepler-452b might mean no water and therefore, no recognisable life.

What about having a magnetic field – does it have that?

All these possibilities mean that even a planet exactly the same size as Earth, orbiting a star identical to our sun on an orbit that takes exactly one year might still be an utterly alien world. Conditions on a planet’s surface are dictated by a myriad of factors – including atmosphere, magnetic fields and planet interactions, which we currently have no way of measuring.

You know, after the whole global warming hoax, you would think that NASA would have learned their lesson about sensationalizing wild-assed guesses in order to scare up more research money from gullible taxpayers who watch too much Star Trek and Star Wars.

The best answer to this is for parents to make sure that their kids are learning the facts about astrobiology from books like “The Privileged Planet” and “Rare Earth”, where the full list of requirements for a life-supporting planet will be found. Pity that we can’t rely on taxpayer-funded public schools to do that for us, because they are too busy pushing Planned Parenthood’s sex education curriculum and global warming fears, instead of real science and engineering.

6 thoughts on “Is Kepler-452b an Earth-like planet? Does it support life?”

  1. Please help me to understand what is the Christian apologetics general take on space exploration or SETI-type endeavors? Is it considered futile to invest in this type of work since the odds that another life sustaining planet exists are so exponential and unlikely that God created additional intelligent life elsewhere?


    1. The issue is whether life can emerge spontaneously or whether an intelligence needs to be involved. The more the naturalists at NASA try to imply that life emerges spontaneously by accident, the more it shores up a failing philosophy of naturalism. From a fiscal point of view, we should not only be investing in research that is likely to produce a return in the here and now. We are in debt $18.5 trillion, we have no money for waste like this.

      Here’s an example of naturalists reacting to this news as I explained above:


    2. When it comes to SETI specifics and most manned spacecraft, I wholeheartedly agree with WK. When I was an a-theist, I had that SETI computer program on my computer (it crashed it BTW) and thought I was neato kewl – my gift to the Cosmos. (gag, pardon me :-)) But, it turned out that the examination was being performed in a cluster that actually could NOT have life in it. Sagan thought that the more stars in a cluster automatically meant the higher probability of finding ET, but it turned out to be a region hostile to ANY forms of life, not merely intelligent ones.

      However, on the more general question of space exploration, I think that SOME of this work, be it astronomy-related or small efficient unmanned spacecraft like JPL specializes in and does well usually – CAN have a big return on investment in two ways:

      1. It can provide us with the kinds of evidence that we need to support the God Hypothesis.

      2. It can provide us with the kinds of evidence that we need to refute the No God Hypothesis.

      On 1, we can look at the great record of astronomy to show that Premise 2 of Kalam (the universe began to exist) is all-but-proven. These small spacecraft have confirmed that these habitable zones are indeed very narrow. The BGV Theorem, proven by 3 agnostics that continue to be agnostics, has DEMOLISHED most blind faith attempts at a self-existing universe. So much so that Hawking, who admits Premise 2, has doubled down on the universe creating itself! His is a case study in the Cosmic Authority Problem and the absolute requirement for the existence of Hell. He is a brilliant scientist who had some theories helpful to laying the groundwork for the BGV Theorem and who has all the evidence in front of him and knows the philosophical implications of it – yet sets it aside to reject his personal Creator Who spoke 100 billion galaxies into existence out of (literally) nothing.

      On 2, we see that these spacecraft flying by planets not only confirm that there cannot be life there but give us an imagery appreciation for the awesome handiwork of God. The imagery from the Hubble Space Telescope, which I was blessed to work on, has been a gift to Christian theism in much the same way that ultrasound has been a gift to pro-lifers. Even some of this SETI-like work is not totally useless as it continues to show the folly of the naturalistic worldview. How many people are being led to the Lord because space scientists continue to jump the gun and then are forced to apologize after the fact for their emotion-laden blind faith in ET and naturalistic a-theism?!?

      I don’t see anything directly inconsistent with small, earth-based astronomy and small inexpensive unmanned spacecraft targeted efforts and Christian theism. They would both seem to be consistent with Psalm 19 and the Parable of the Talents.

      My big thing is that I think we should be engaging in these endeavors more with Christians who are scientists, because that will allow us to use the funds more efficiently, and less randomly, as our prism is vastly superior to theirs. The costs associated with small unmanned spacecraft and astronomy are tiny, infinitesimal compared with probably one small state’s yearly involvement in ObamaCare, which is a country destroyer, an On-Earth “Asteroid,” if there ever was one.


  2. “You know, after the whole global warming hoax, you would think that NASA would have learned their lesson about sensationalizing wild-assed guesses in order to scare up more research money from gullible taxpayers who watch too much Star Trek and Star Wars.”

    Yes! A new addition to your Hall of Quotes! (Getting crowded in there – might need to expand the museum. :-))

    Seems like every time I get a question on something, you post a great reply the next day. (Perhaps you need to move your posts up by one day?!? :-)) Just yesterday, I got a question on this, and was smart enough (thanks to your earlier posts) to understand the various habitable zones. But, I couldn’t quite go to the next level on if this story was sensationalist or not. This guy was really excited. All I could tell him was that if I had a dollar for every false ET life claim by a-theists, I could have retired earlier than I did! So thanks, WK – he will be getting this!

    PS. Don’t be too hard on Star Trek, Original Series: there is some good fodder for God discussions, the nature of time, cosmology leading to God, and objective morality leading to God in there. (“City on the Edge of Forever,” etc.)


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s