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Big Impact: A Cosmic Collision
Heidi B. Hammel joined The Planetary Society's Board of Directors in 2005. A Senior Research Scientist with the Space Science Institute in Boulder, Colorado, Hammel herself lives in Ridgefield, Connecticut.
She received her undergraduate degree from the Massachusetts Institute of Technology in 1982 and her Ph.D. in physics and astronomy from the University of Hawaii in 1988. After a post-doctoral position at the Jet Propulsion Laboratory (Pasadena, California), Hammel returned to MIT, where she spent nearly nine years as a Principal Research Scientist in the Department of Earth, Atmospheric, and Planetary Sciences.
Hammel primarily studies outer planets and their satellites, with a focus on observational techniques. Hammel received the 2002 American Astronomical Society's Division for Planetary Sciences (AAS/DPS) Sagan Medal for outstanding communication by an active planetary scientist to the general public .
Question: What are scientists doing to protect us from cosmic collisions?
Heidi Hammel: From that comet crashing into Jupiter, we actually learned quite a bit about cosmic collisions. And you can put them in different categories. One of the first things we learned was these collisions happen on human lifetimes. This isn’t stuff that happened a billion years ago. This is going on right now, here in our solar system, massive collisions. And when I say massive, we took one of our impact sites that we had on Jupiter, and someone took it and mapped it onto a globe of the earth. Oh, it’s scary, you know. If one of these things hit the earth, we’re talking major disruption of the biosphere. We’re talking basically all of us dead. So, gosh, it’s a good thing it happened on Jupiter, not on earth. But at the same time, I mean, it was happening for real, and we could all see it. So it made the concept of cosmic collisions a very real concept on the large scale. Most people have already seen a cosmic collision. If you’ve seen a shooting star ever, you’ve seen a cosmic collision, because a shooting star is not a star. It’s a tiny dust or pea sized fragment of an asteroid or a comet hitting our atmosphere and burning up as it hits in, as it comes in. But those are tiny. It’s the big ones when they hit that could really do some serious damage to the planet and to the biosphere, the people and animals and plants and stuff living on the planet. So Shoemaker-Levy 9 made that real for us. We also learned quite a bit about the atmosphere of Jupiter. Now, you have to remember astronomy is almost always a passive science. Scientists normally like to do experiments. You know, they like to mix this with that and see what happens. They like to take this thing and poke it and see how it reacts. In astronomy we can’t do that. The stars, the planets, the galaxies, are so far away that we just look at them, and we have to learn things by looking at them. But in the case of Shoemaker-Levy 9, nature provided us with some ink that it injected into the atmosphere of Jupiter. The ink was the black material that the comet impacts created, which was basically burned up Jupiter atmosphere, we think. And that ink was dumped into the atmosphere, and then the winds of Jupiter could pick it up and throw it around and move it throughout the atmosphere. What a fantastic experiment for a planetary scientist. It’s like you couldn’t design a better experiment, you know. If I had this like giant pile of ink, inject it into an atmosphere, and watch what happened, you know, that’s what you’d want to do. And Shoemaker-Levy 9 did that. So it allowed us to trace out winds to see which direction they were blowing. Now we knew generally which way most of the winds were blowing in the cloud decks that we see, because we could watch a cloud, or we could watch what the cloud does. But in the upper atmosphere, these clouds are very, very thin and diffuse. And normally we can’t see them or trace them. But Shoemaker-Levy 9 injected chemicals into the upper atmosphere and using telescopes here on earth, we can trace the motion of those chemicals over a period of several years after the impacts, and watch the directions that the winds are blowing in the upper atmosphere. And they were moving more or less the direction that people predicted. The rates were not quite the same. And so that provides us with information we could use to better study the atmosphere of Jupiter itself. We couldn’t have done it without Shoemaker-Levy 9 impacts.
Question: What are scientists doing to protect us from collisions?
Heidi Hammel: Every year they have a conference about planetary protection, because the specter has now visibly been raised at these cosmic collisions actually could happen anytime. So there are scientists and engineers who are actively thinking about ways that we could either deflect an asteroid or comet, or remove the asteroid or comet in some way, move it out of its path. I mean, Hollywood has its own ideas about how to do that. We also have Bruce Willis saving the earth. But in point of fact scientists themselves have been thinking very seriously about how we might deflect an asteroid or comet. And one of the keys is finding them early, because if you find them early enough, and I mean like, 10, 20, 30 years before they’re going to hit the earth, you only need a tiny little push to get them to go off that orbit that they’re on and move them out of the way. It’s the ones that are coming in that you don’t find out about until three days before that, you know, that’s our worst nightmare, because there’s nothing really you can do about it in that case. We have actual programs and telescopes being built now that will have the capability of figuring out the whole population of these earth crossing asteroids. Right now we only know, we think we know about 10% that are out there, 10% of the population. That’s not a happy number, is it, because that means there’s 90% of the objects out there we don’t know about. With some of the large telescopes we’re developing today, we think that within a few, five, ten years of using there large telescopes to map out the whole sky a number of times, repeating, looking for moving objects, tracking their orbits, we think within 10 years we might be able to push that number up to 90%. So we really will have a much clearer understanding of what’s out there that might threaten us. Another big problem, of course, is understanding the bodies themselves. If it’s a comet that’s coming in versus an asteroid, and we think one is rockier and harder, and one is softer and fluffier, and you would want to treat them differently. I mean, you wouldn’t want to take a fluffy thing and then like blow it up, because then you got like a gazillion fluffy bits that are all more or less coming your way. Whereas a hard thing, you know, maybe you could set off like a nuclear bomb to push it off it’s track. So understanding what those space rocks or space ice balls, what they’re physically made of, that’s a big part of the MASA exp
As other planets have demonstrated, says Heidi Hammel, the threat is real. For Earth, an early warning system is critical.
Educators and administrators must build new supports for faculty and student success in a world where the classroom might become virtual in the blink of an eye.
- If you or someone you know is attending school remotely, you are more than likely learning through emergency remote instruction, which is not the same as online learning, write Rich DeMillo and Steve Harmon.
- Education institutions must properly define and understand the difference between a course that is designed from inception to be taught in an online format and a course that has been rapidly converted to be offered to remote students.
- In a future involving more online instruction than any of us ever imagined, it will be crucial to meticulously design factors like learner navigation, interactive recordings, feedback loops, exams and office hours in order to maximize learning potential within the virtual environment.
Placing science and religion at opposite ends of the belief spectrum is to ignore their unique purposes.
- Science and religion (fact versus faith) are often seen as two incongruous groups. When you consider the purpose of each and the questions that they seek to answer, the comparison becomes less black and white.
- This video features religious scholars, a primatologist, a neuroendocrinologist, a comedian, and other brilliant minds considering, among other things, the evolutionary function that religion serves, the power of symbols, and the human need to learn, explore, and know the world around us so that it becomes a less scary place.
- "I think most people are actually kind of comfortable with the idea that science is a reliable way to learn about nature, but it's not the whole story and there's a place also for religion, for faith, for theology, for philosophy," says Francis Collins, American geneticist and director of the National Institutes of Health (NIH). "But that harmony perspective doesn't get as much attention. Nobody is as interested in harmony as they are in conflict."
Studying voice recordings of infected but asymptomatic people reveals potential indicators of Covid-19.
A leading British space scientist thinks there is life under the ice sheets of Europa.
- A British scientist named Professor Monica Grady recently came out in support of extraterrestrial life on Europa.
- Europa, the sixth largest moon in the solar system, may have favorable conditions for life under its miles of ice.
- The moon is one of Jupiter's 79.
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A study finds people are more influenced by what the other party says than their own. What gives?
- A new study has found evidence suggesting that conservative climate skepticism is driven by reactions to liberal support for science.
- This was determined both by comparing polling data to records of cues given by leaders, and through a survey.
- The findings could lead to new methods of influencing public opinion.