Is a Minor in Astronomy a Good Complement to One’s Chosen Major Subject?

Question: I major in business but want to minor in astronomy is that a good choice?  — Josh

Answer: I think that a minor in a science, like astronomy, can only be a plus for the work that you will do in your major.  For example, for a business major I would think that an understanding of physics would be a useful skill set to have.

Jeff Mangum

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Values for the Terms in the Drake Equation

Question: I am conducting research on the Drake Equation.  I am having trouble locking down set values.  I can only find estimations of the viable planets but what I need are the actual numbers to plug into the equation.  Can you help?  — Christopher

Answer: The Wikipedia page on the Drake Equation contains some estimates, both past and current, for the variables in the Drake Equation.  You might want to start there, then follow some of the references associated with each quantity to assess its viability.

Jeff Mangum

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A Career in Astronomy and Access to Astronomy Classes

Question: Hello. I am a college student, and I am extremely interested in astronomy. I am taking math and chemistry but my school doesn’t offer astronomy classes. Can I still get a career in astronomy with a degree in chemistry or would it be best to try and transfer to a school that offers astronomy?

Also, I’m worried I won’t be smart enough to succeed in astronomy. I was a valedictorian in high school, but I’m still worried to take the risk of transferring schools for an astronomy program and then not be able to complete it. Any advice? Thank you.  — Kristin


Answer:  Most astronomers are actually trained as physicists or chemists who later specialize in the astrophysical application of physics or chemistry.  I would not worry too much about the lack of access to astronomy classes at your undergraduate school.  It is more important to take as much physics and math, and chemistry if your ultimate goal is to study interstellar chemistry, that you possibly can so that you can have a good grounding in these subjects, which are fundamental to astrophysical research.  Also, having a good background in physics, chemistry, and math allows for you to have many options for career path in addition to astronomy.  Finally, pursuing a career in astronomy is not all about “smarts”.  A strong desire to study the universe is often more important than being “smart”.  In the end, if you decide to pursue a career in astronomy you need to be certain that it is what you want to do in life, and that is the most important aspect of one’s choice of career.

Jeff Mangum

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Alternate Theories for the Expansion of the Universe

Question(s): I have three related questions:

  1. The redshift of objects indicates that the farther away they are, the faster they’re moving, but wasn’t the observed light emitted millions of years ago, when the object wasn’t so far away?  How do we know what velocity it’s moving at now, or if it’s even there?  Have we measured the velocities of known objects over ‘long’ periods of time to see if their velocities are changing, either speeding up or slowing down?
  2. Rather than a ‘big bang’ with the Universe being created and expanding into nothing, isn’t it possible that it was a ‘big bubble’ similar to nucleate boiling, and that we are surrounded by ‘stuff’ into which we’re expanding?
  3. If we are expanding into stuff,  couldn’t the cosmic background radiation be coming at us from outside the boundaries of our Universe?  Could ‘dark’ energy and matter be external also?  — Larry


  1. You are correct in that the light emitted from distant objects that we observe today was emitted from the distant object in the past, its speed in getting to us limited by the speed of light.  We do not have a way to measure an object’s velocity “now”, but we can measure the velocities of objects at a range of distances from us.  This allows us to sample the expansion rate of the universe at a range of distances, and therefore measure the speed-up or slow-down of the universe’s expansion.
  2. The suggestion that the universe is expanding into other “stuff”, like any alternate theory of the expansion of the universe, requires a way to test its observables.  This is the problem with most alternate theories.  How would you measure the “stuff” into which our universe is expanding?  I don’t believe that it is possible to measure the material into which we might be expanding, so this alternate theory really is not viable.
  3. I am not aware of any observations which would allow for the cosmic microwave background and dark energy to be derived from an external body of matter.  At this point, this would be a theory which lacks observations to support it.

Jeff Mangum

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Advice for Purchasing a First Telescope

Question: I am purchasing my first telescope and for good viewing of Saturn, Mars, Jupiter and the Moon, am I best to buy a 130mm aperture or 200mm aperture telescope?
Also, I’m deciding whether to go with a telescope that comes with a tripod, like Celestron Astromaster. Or a Dobsonian Skywatcher that doesn’t need one.
What are the pros and cons to having or not having a tripod?  — Michelle

Answer:  For observing objects like planets or the Moon a telescope with a smaller aperture is sufficient (and likely less expensive).  If you decided to try to observe deep-sky objects like star clusters or galaxies, you might need a larger aperture.  Regarding your second question about tripod or Dobsonian mount for your first telescope, let me point you to the Stargazer’s Lounge, where this question was in fact addressed.  Hopefully you can find some useful answers in the responses to this question there.

Jeff Mangum

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What Should a Budding Astronomer Look for in a College?

Question: Hello, I’m a senior in High School and have been planning on being an astronomer for years. I was curious as to what college may be best for an astronomy or physics degree? I have good grades but don’t want to go to a very difficult college. I’m planning on getting a PhD and would like to find a college that is easygoing but has good education.
Help would be appreciated, thank you!  — Brittany

Answer: Your best course of action is to find a college that you both like and also has strong physics, math, and computer science programs.  With strong programs in these areas you will improve your chances of getting a good education in the primary skills that you will need as a professional astronomer: physics, mathematics, and computer science.

Jeff Mangum

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What Educational Degrees Do Most Astronomers Have?

Question: Hey Jeff – I have been looking around your “Careers in Astronomy” thread and cannot seem to find this question.

What is your actual degree in astronomy?
I would like to know as I am about to do a greater project about Astronomy for my senior year in High school and would like to use you as a source, which demands that I have knowledge of your degree as an expert.

Best wishes from an astronomy enthusiast in Denmark.  — Daniel


Answer: Like most professional astronomers, I have a Doctorate (Ph.D.) degree.  I also have Masters and Bachelors degrees, and all of my degrees are in Astronomy.  Now, professional astronomers generally have Bachelors and Ph.D. degrees in one of the physical sciences; principally physics, chemistry, or astronomy.  We also tend to have strong backgrounds in mathematics and computing, which are the primary tools, in addition to physics, that astronomers use to conduct their research.

Jeff Mangum

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What Was That Bright Light in the Sky Over the Southwestern US on November 7, 2015?

Question: On Nov 7th around 7PM in Tucson, we observed a very unusual sight in the sky, one that I have never seen before.  I believe it might have been related to the missile test off CA, but the way it manifested itself here was very bizarre.  We first observed a large circular light area against the black night sky in the west, probably around 30 degrees in diameter, fairly bright and very distinct as a white glow.  More faintly there was a conical greenish glow, a bit fainter, in the center of this area, looking somewhat like a largish comet.  This appearance did not change for perhaps 20 mins but was stationary in the western sky.  We also noticed just off to the north, a faint white “track”, vertical, as if something had launched into the sky.  It was about 20 degrees in length.  Again, lasted for some time.  I wonder if this isn’t some sort of projection of the events in the Pacific, happening around sundown out there?  Could it be related to the geomagnetic storm?  Did almost have an aurora appearance?  — Tim

Answer: This light in the sky was widely reported by quite a few people.  Apparently it was an unarmed Trident missile that was test-fired from a submarine off the coast of Southern California.

Jeff Mangum

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Is That a Constellation on My Necklace?

Question: Hello, I just had a question about a constellation. I don’t know how to insert a picture so I’m just going to describe it. I got a necklace with a constellation that looks like Cancer, except there’s an extra star at the end of the point that goes to the right. I was wondering if this was an actual constellation or something made up because I tried to find constellations with 6 stars that looked like it. I’m not quite sure if you can picture it, but thanks for the help if you can in any way!  — Meleena

Answer: This does not sound to me like any constellation that I am familiar with.  You might want to try the StarDate Constellation Guide to see if you find a match.

Jeff Mangum

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Can Event Horizons be Created at Lagrange Points in a Multiple Neutron Star System?

Question: I have been interested in astronomy since I was a child. My question arose while I was studying the effects of Lagrangian points between multiple bodies.

Imagine a scenario of a binary (or multiple) neutron stars system. Provided the neutron stars are all very close to their critical mass and are running in a very compacted orbits around each other. Is it possible that the gravitational interaction between the neutron stars, similar to the principle of Lagrangian points, creates a spot of event horizon in the system?

I am deeply intrigued in this question, as I imagine the event horizon would be mobile and deforms corresponding to the motion of neutron stars. Also, with no singularity in the system, the event horizon would probably behave differently compare to those around a black hole.  — Peterson

Answer: As you likely already know, Langrange Points are positions where the gravitational pull of two massive objects, such as the Earth and the Sun, precisely equals the centripetal force required for a small object to move with them.  This is quite different than an event horizon, which is a boundary in space-time beyond which information cannot be transmitted.  In other words, objects which are within an event horizon cannot be detected from an observer outside the event horizon.  Event horizons are associated with very massive objects, such as black holes, which create gravitational fields that are so strong that they halt the travel of light propagating from the black hole.  Neutron stars are not massive enough to produce event horizons.  Also, Langrange Points do not naturally have the physical properties to create a massive object that can lead to an event horizon.

Jeff Mangum

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