Astronomy 104
Spring 2026,
Sections 1 through 4.

These are introductory courses to astronomy, with more emphasis on active thinking than memorizing facts. The main points of this course are (1) a general understanding of astronomy, (2) what can be observed in the sky, (3) the Solar System in 103 / the stars and the Universe in 104.

ANNOUNCEMENTS
WELCOME TO ASTRONOMY!

TEST 2 (originally March 20) has been canceled.
A heavy rewiew quiz on deep -sky objects is coming up on Monday, March 22.
For details, see the 'Presentation' link below.

 Pass-fail test is coming up on March 27.


Students must have a scantron (#16485) and a pencil (no pen) for each class.
(This adds up to ~25 scantrons for the whole semester.)



What's up in the sky?

 
Solar Activity  is in full swing now, lots of sunspots.
Click for today's look.



 New Moon: Mar. 18,   First Quarter:  Mar. 25
 Full Moon: Apr. 1,  Last Quarter: Apr. 10.
***
Planets:

Jupiter and Neptune are visible early night.

******

News

1. We now have found the third interstellar comet, 3I/ATLAS.
2. Sat
urn has 128 new moons discovered, raising the total  to 247.
3. The second closest star (system)to us, Barnard's star, has four planets.
  4. New models of the NASA's DART impact reshaping the asteroid moon Dimorphos show that this object is 'rubble all the way down'.


*****

Unusual events and objects

(Students might want to ask help in how to use the coordinates, ephemerids and finder charts.)