Starship Asterisk*

Thank you! Good source of information and an excellent map.

--Bill

Are the Milky Way and other galaxies in the Local Group considered part of the Virgo Supercluster?

--Bill

Thanks, Chris! I'm a recreational amateur astronomer with very little formal education in science. When I found a diagram of the proton-proton process, I didn't understand where all the neutrons were coming from. By the way, I suggested your Cloudbait site to a friend in the Memphis Astronomical Soc...

When hydrogen atoms are converted to helium atoms in the sun in the proton-proton process, where do the neutrons come from that are part of the helium atoms? The hydrogen atoms had no neutrons before the fusion process takes place.

--Bill

Art & Chris,

Thanks very much. This helps put it in perspective. For people without much education in science (like myself), a trillion electron volts sounds like something that would blow holes in walls because of thinking about it in terms of common electrical voltage.

--Bill

In reading about cosmic rays, I learned that common, low-energy cosmic rays have an energy level of one trillion electron volts (eV). Medium- and high-energy cosmic rays have levels much higher. How can you explain the concept of "electron volts" to people (like myself) who have little or ...

I found an excellent discussion of cosmic rays on the Pierre Auger Observatory site. I would suggest this site for anyone who might be interested in cosmic rays. It was interesting to learn that about 200 low-energy cosmic rays per second strike every square meter on earth. This charged particle rad...

Mark & Chris, Thanks for your help! I'm curious about this because when I discuss cosmic rays I think someone may ask how often we are being hit by them, etc. I know the heliosphere blocks some cosmic rays, and the earth's magnetic field blocks some more. Some get through, however, to strike the...

In reading about cosmic rays, I have not been able to find any infomation about their frequency--about how often they strike the earth's atmosphere. Frequency is described as being greater at the poles than at the equator. But I haven't been able to find any numbers. Are we constantly being bombarde...

Thanks for your suggestion, Orca.

--Bill

Thanks, Art. Learned something new.

--Bill

In one of the topics below, the author mentioned that the solar system is in--or moving into--the Orion Arm of our galaxy. I thought our solar system occupied a relatively fixed position in the Orion Arm, and that the arm itself rotated around the core of our galaxy carrying the Sun and other stars ...

Thanks very much, Chris. I've volunteered to give a presentation about the Sun for our astronomy club at a county park system nature center next month. I plan to discuss the life cycle of the Sun, mentioning that the Sun will become hotter over time, etc. I figure someone in the audience might ask w...

I've read that scientists believe the Sun's temperature increases by about 10 percent every billion years or so. In about a billion years, they estimate the Sun will get so hot that it will boil away the oceans on Earth.

What is causing the Sun's temperature to increase over time?

--Bill

Thanks to the Pierre Auger Observatory and to forum members here for help in locating an "active" galaxy that I can refer to in my park-system presentation, and then point to with my laser in the stargazing session that follows. The Pierre Auger staff suggested using elliptical galaxy M87 ...

geckzilla,

Thanks very much for your help! I'll check the sources you cited. I would be delighted if M82 qualifies as an active galaxy.

--Bill

P.S. I'm in northeast Ohio in the U.S., latitude 41 north.

Thanks. I'm looking for sources of intergalatic cosmic rays. I know about Centaurus A, but it appears to be at or below our horizon throughout the year. Not good for my purpose. I would like to find an active galaxy near an easily recognized constellation that I can point to with my laser at public ...

Thanks for your suggestions!

--Bill

Does anyone have a list of "active" galaxies that are considered possible sources of cosmic rays? I've tried an Internet search and have found information about active galaxies and cosmic rays, etc., but so far haven't been able to find a list of active galaxies. Our astronomy club is givi...

I remember reading that the Sun may have been created as part of a cluster of stars, and that these stars have since drifted away. The article mentioned that scientists think that stars created in a cluster with the Sun may be travelling through space along with the Sun on parallel tracks perhaps ab...

Thanks, Art. I was hoping to use M82 as an example of possible sources for cosmic rays. We have a public star party coming up next month, and M82's location near the Big Dipper would have made it a perfect example for use with a laser pointer.

I'll have to try something else.

--Bill

Is M82, the "Cigar Galaxy," one of the "active" galaxies that are considered a source of high-energy cosmic rays?

--Bill

Thanks, Mark!

I've read that a gamma ray burst (GRB) that happened to hit the Earth could possibly destroy half our ozone layer. How close would such a burst have to be to cause this kind of damage damage?