Astronomy 2141 - Life in the Universe, Spring 2026

SYLLABUS: MWF 11:30-12:25 PM, Scott Lab E125

The exam questions will be from the material covered in class. The daily topics listed below cover only the main points. Make sure to attend lectures and study powerpoint lecture files below. Exam questions are composed of multiple choice questions to test basic concepts. You are expected to know important facts, figures and the meaning of equations.

DAILY TOPICS

• Jan 12, Monday: Overview of syllabus - Extraterrestrial Life; Basic Astronomy - no proven connection between astrology and astronomy; since stars also move, the position of the Sun relative to the 12 Constellations of the Zodiac changes over centuries and is different from the dates given in the 'horoscope' section of newspapers; science and religion: faith vs. inquiry; ancient astronomy; use of Geometry by the Greeks, belief in the Geocentric system (Aristotle,Ptolemy), Geocentric model (Ptolemy) vs. the Heliocentric model (Copernicus); the Metric system - used in science and in all countries except the U.S.; powers of ten in exponents; Universal spatial and temporal history; observational astronomy.
• Jan 14, Wednesday: Ground and space astronomy - need space observations to cover all kinds of radiation, such as X-ray, UV, etc. that are absorbed by the atmosphere of the Earth. The distance scale; angular size; the Earth moves about 1 degree in its orbit around the Sun each day; basic fundamental constants such as speed of light, 1 AU = (E-S) distance, etc. distance measures in astronomy are the AU and the Light year (LY); parsec - another distance unit is based on the method of parallax.
• Jan 16, Friday: Angular distances; the Earth moves about 1 degree in its orbit around the Sun each day. PARALLAX: apparent change in angular position due to motion; define 1parsec (pc) = 1/alpha(arcseconds), where alpha is the angle usually mesured relative to the orbit of the E-S orbit. The Celestial Sphere - stars 'fixed' in the Sky as a globe; Ecliptic - path of the Sun in the Sky; Celestial Equator - extension of Earth's equator to the celestial sphere; Vernal (Spring) and Autumn Equinoxes and Summer and Winter Solstices, related to seasons. Celestial 'longitude' - Right Ascension, Celestial 'latitude' - Declination, enable the location of an object in the Sky.
• Jan 19, Monday - MLK Hoiliday
• Jan 21, Wednesday: Life: Life in the universe; Definition: DNA - made of common light CHON elements; search for extraterrestrial life - SETI; criteria for existence; organic molecules; Miller-Urey experiment; probability of finding life: Drake equation; physical requirements: solar type stars, number of stars, "intelligence", etc., candidates for life within solar system.
• Jan 23, Friday: Extra-solar planets, recent discoveries; "Hot Jupiters"; techniques for discovering exoplanets; Kepler spacecraft; Habitable "Goldilocks" zone with liquid water. Age, time: astronomical, geological and climate timescales, radioactive dating, half-life.
• Jan 26 Monday: Planetarium show in Arne Slettebak Planetarium on 5th Flr of Smith Lab; homework assignment: write 10 points from the planetarium show and submit online to TA (one page).
• Jan 28: Wednesday: Big Bang, Hubble's law, expansion and age of the Universe, matter, atoms, Periodic Table. PopQuiz 1 (last 10 min of class, 5 questions)
• Jan 30, Quiz 1
• FINAL EXAMINATION: May 1, FRIDAY, 12:00-1:45 PM, online via carmenzoom. All comprehensive final exam, 100 multiple choice questions

  Powerpoint files

• Lecture File 1
• Lecture File 2
• Lecture File 3
• Lecture File 4
• Lecture File 5
• Lecture File 6
• Lecture File 7
• Lecture File 8
• Lecture File 9
• Lecture File 10
• Lecture File 11
• Lecture File 12
• Lecture File 13
• Lecture File 14
• Lecture File 15
• Lecture File 16
• Lecture File 17
• Lecture File 18
• Lecture File 19
• Lecture File 20
• Lecture File 21
• Lecture File 22

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  Revised: Dec 29, 2025