Astronomy 104, Spring 2015, Sections 1-2-3-4.

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.


Test 3 has been graded.

All grades are up to date as of Apr. 21.

In all classes and for all tests,

students need a new scantron # 16485,

one scantron for each class.

What's up in the sky?

The Sun.
There are quite a few sunspots now!

New Moon: Apr. 18, First Quarter: Apr. 25,

Full Moon: May. 4, Last Quarter: May. 11.


Venus is observable only right after sunset, is very bright (-4 mg), but looks little (15 as) in the telescope.

Jupiter is up all night, and it is great in a telescope.

Saturn rises at 10:30 pm, but is observable only after midnight.



1. The Dawn spacecraft spots two very bright spots on Ceres, probably ice deposits. Looks quite striking.

Click here for the image and explanation.

2. Philae, a space probe off the Rosetta spacecraft,

has landed on comet Churiumov-Gerasimenko after bouncing up twice.

It seems it landed in a hole, and hybernating for lack of power.

An important result of the mission: Earth's water did not originate in comets.


Unusual events and objects

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