Answered Questions

In terms of habitability, Mars and Venus seem like near-misses and so our own solar system might easily have had more than one habitable planet. Do you think that in other solar systems where there is life, a significant number will have more than one habitable planet?

The question of the width of the habitable zone in our solar system is complex. Both Venus and Mars have been described as near the edge of the habitable zone, as you note. The situation is even more complicated, however, since the habitable zone has shifted outward over the past 4 billion years as...

September 15, 2008 More

I have been reading about exoplanets from various sources and I have noticed that generally all giant planets like jupiter and saturn are composed of gas and small planets like earth and mars are generally solid. Is there an explanation for this? and also is there any evidence of giant rocky planets as big or bigger than jupiter for instance.

In many cases we do not know anything about the composition of exoplanets, just their mass. In a few cases there is additional information, which indicates that the giant exoplanets are composed in large part of gas, like Jupiter and Saturn in our solar system. This is probably the case because as a planet...

September 12, 2008 More

Could you please let us know about Nibiru? If it does not exist, why then is there so much hype? Why does the fly-by of this planet coincide with the Mayan's and Egyptians prediction that the world will end? We want concrete proof from NASA that it does not exist please.

Your request for concrete proof from NASA that Nibiru does not exist is illogical. The burden of proof should on those who make claims that Nibiru is real. They have no evidence whatever, and you should not be fooled by their unsupported claims.

David Morrison
NAI Senior Scientist

Can you please tell me if there is a scientific reason why Earth & its Solar System could not possibly have been made first in the universe and everything else follow? If everything else followed (at the speed of light, assuming light is constant in the universe), then what we see in space today is not the past back beyond the creation of Earth?

The Earth (and solar system) are 4.56 billon years old, while the universe is between 12 and 13 billion years old. A lot of modern astronomy involves looking back to times much older than the age of the solar system. If you checked the observing logs of many large telescopes, you would find that...

September 10, 2008 More

What are you going to do when the destruction of earth starts when Nibiru's magnetic field affect the Earth? As you know the Earth will encounter storms, giant tsunamis, hurricanes, the flip of the poles. And will sure enough kill the most of the earth's population. You must have a plan, to save the world's important people, to not let the human race become extinct. I understand why you have not informed the public. But what are you going to do. You must know some of the interpretations of the crop circles that I worked on, they state clearly how our race must act and what we must do to survive.

Nothing that you write in your question is true. Nibiru does not exist (by that or any other name), and no wayward objects are coming into the inner solar system. Since it does not exist, it has no magnetic field. Also, there is no alignment of planets or of the Sun with the...

September 9, 2008 More

Real science is predicting the next/current sun cycle to be the worst in 50 years. The first two sunspot's of 2006 are moving in reverse direction.On the winter solstice of 2012, the noonday Sun exactly conjuncts the crossing point of the sun's ecliptic with the galactic plane, while also closely conjuncting the exact the center of the galaxy. To what extent is this fact true?Is it going to cause any harm to mankind or normal course of life??

Much of what you are attributing to "real science" actually is not true. While astronomers a couple of years ago were predicting that the next solar maximum would be higher than normal and occur around 2012, these predictions have been revised in view of the very slow (or late) start of this solar cycle...

September 8, 2008 More

My questions concern the K-T impact event that is currently theorized to have lead to the extinction of the non-avian dinosaurs. Would the impact have been powerful enough to blast debris into space and could any of it have settled on the moon? Where on the lunar surface would one expect to find this debris? Would it be macroscopically identifiable as terrestrial in origin or would sophisticated lab analysis be required?

The KT impact of 65 million years ago in what is now the Yucatan in Mexico is estimated at an energy of 100 million megatons of TNT. It formed a crater about 200 km in diameter and as much as 40 km deep -- enough to pierce the crust and reach the upper...

September 5, 2008 More

I have heard it said that we will never find another civilization of humans in the universe to communicate with. My question to you is why do astronomers and astrobiologist live by this belief? Given a tremendous volume of stars, and a never ending process of planet formation in the universe, wouldn't the possbility of humans on another planet somewhere at least exist? And if so, even with a lack of evidence, why does Astrobiology not entertain this prospect even more?

There may be a problem here with semantics. I have never heard any scientist assert that we were the only intelligent technological life in the universe. That would be absurd. The idea of many inhabited worlds is central to the science the astrobiology. On the other hand, we certainly will...

September 4, 2008 More

I realize everything that is said on 2012 is an internet hoax. The only concern I still have is the next solar storm in 2011 or 2012. I heard on PBS that the rays from the solar storm are blocked by our Earth's magnetic field. I also heard from another source that our magnetic field is getting weaker and it is almost not there. Do you know how well our magnetic field can protect us from the next solar storm.

Don't worry about the next solar maximum; this happens every 11 years (approximately) and is no danger to life on Earth. The small fluctuations in the Earth's magnetic field are also not a concern; our magnetic field is plenty strong enough to protect us and is very unlikely to decline (or reverse) for thousands...

September 3, 2008 More

I was reading some NASA articles when I found one from 2006 (Here's the article: http://www.nasa.gov/vision/universe/solarsystem/10mar_stormwarning.html), talking about a massive solar storm that will hit the earth in 2011 or 2012, it wasn't certain. My question is, it will affect the life on Earth? If yes, how? I did see in some forums that it would affect drastically the magnetic field of the Earth but...All I know about this stuff of Solar Storm is that they can mess up with satellites.

Scientists cannot predict solar storms years or even months in advance, just as we cannot predict individual hurricanes on Earth. What we can predict is the 11-year cycle of solar activity. We are currently going through the minimum activity, with the first sunspots of the new cycle having appeared early in 2008. The next...

September 2, 2008 More