Introduction to modern astronomy12
島袋隼⼠(Hayato Shimabukuro)（云南⼤学、
SWIFAR）
©GETTYIMAGES

What is the solar system?
•Solar system（太阳系）contains Mercury（⽔星）, Venus（⾦星）, Earth（地球）, Mars
（⽕星）, Jupiter（⽊星）, Saturn（⼟星）, Uranus（天王星）, Neptune（海王星）

美少女战⼠
©武内直⼦

美少女战⼠
©武内直⼦

美少女战⼠
©武内直⼦
?

The definition of planet
•Pluto（冥王星）was once one of the planets of the
solar system.
•But, International Astronomical Union(IAU) decided to
remove Pluto from the solar system in 2006
•So far, we have no definition of a planet.
•The definition of the planets has been established.
1. Planets go around the sun.
2. Planets have a spherical shape (more technically, it keeps a spherical shape due to
gravitational equilibrium.)
3. Planets wipe out other astronomical objects from around their own orbit.

The definition of planet
•Pluto（冥王星）was once one of the planets of the
solar system.
•But, International Astronomical Union(IAU) decided to
remove Pluto from the solar system in 2006
•So far, we have no definition of a planet.
•The definition of the planets has been established.
1. Planets go around the sun.
2. Planets have a spherical shape (more technically, it keeps a spherical shape due to
gravitational equilibrium.)
3. Planets wipe out other astronomical objects from around their own orbit.

•Pluto does not satisfy this requirement. Thus, Pluto is removed from the planet.
Pluto is defined as a dwarf planet now.
The definition of planet
3. Planets wipe out other astronomical objects from around their own orbit.

The size of planets
•If we set the earth is 1, then…
Mass Radius
地球 1 1
⽔星 0.055 0.38
⾦星 0.815 0.95
⽕星 0.107 0.53
⽊星 318 11.2
⼟星 95.2 9.45
天王星 14.5 4.01
海王星 17.2 3.89
太阳 109
3.33 × 105

T2
1 /R3
1 = T2
2 /R3
2
Kepler’s laws
A=B=C

How did solar system form?

How did solar system form?

How did solar system form?
•Planets are forming around HL-tau star.

Exploring solar system
•Humans have been actively exploring the Moon and Mars (USA, Russia, China, Japan,India)
Scientific purposes
•Is there any evidence of life?
•Can we live in Mars?
•Development of the Moon as the next step to other planets

Exploring solar system
•Humans have been actively exploring the Moon and Mars (USA, Russia, China, Japan,India)
Scientific purposes
•Is there any evidence of life?
•Can we live in Mars?
•Development of the Moon as the next step to other planets

Exploring the moon
•The history of lunar exploration is long.
•In 1969, humans landed on the moon for the first time
(Apollo 11). They brought back large quantities of moon
rocks and sand.
(Apollo 11)
It is helpful to understand the science of the moon.
嫦娥
•China sends Chang’e (嫦娥) to the moon
and they also brought back the rocks of the
moon.

•NASA(USA) and other partners are planning to send
humans to the moon again (Artemis Program).
The launch of Artemis 1 on 2022/11/12
•NASA plans to build sustainable bases on the
lunar surface and in lunar orbit and use them as a
stepping stone towards the next major
breakthrough - a manned mission to Mars.
Gateway project
Exploring the moon in the future

•NASA(USA) and other partners are planning to send
humans to the moon again (Artemis Program).
The launch of Artemis 1 on 2022/11/12
•NASA plans to build sustainable bases on the
lunar surface and in lunar orbit and use them as a
stepping stone towards the next major
breakthrough - a manned mission to Mars.
Gateway project
Exploring the moon in the future
From the moon to Mars!

Astronomy in the moon
Lunar Crater Telescope FARSIDE 鸿蒙计划
•We are currently planning to the moon for astronomy.
Why?
•The moon is radio quiet environment.
•Main science topic in the moon is “First stars and galaxies
in the universe”

Exploring the moon in the future
In the near future, can we live on the moon??

Exploring solar system
•Humans have been actively exploring the Moon and Mars (USA, Russia, China, Japan,India)
Scientific purposes
•Is there any evidence of life?
•Can we live in Mars?
•Development of the Moon as the next step to other planets

Exploring solar system
•Humans have been actively exploring the Moon and Mars (USA, Russia, China, Japan,India)
Scientific purposes
•Is there any evidence of life?
•Can we live in Mars?
•Development of the Moon as the next step to other planets

『火星救援 (The Martian)』

『火星救援 (The Martian)』

Exploring the Mars
Why Mars?
•Is there a life on Mars?
•Can humans live in Mars?
『火星救援』
•What kind of resource can we get on Mars?
•Were there oceans on Mars
etc
Curiosity
•NASA sent “Curiosity”, which is Mars exploration
rover.
•It found that Mars once had sea and chemical
component which is necessary for keeping life.
Mars has (had) life??

Exploring the Mars

Exploring the Mars

Summary
• Our solar system includes 8 planets(including the earth)
• At
fi
rst, the sun formed and then planets formed around
the sun from nebulae gas
• Human currently tries to develop environment in the moon
and the mars.

Mid-term examination!
We will have a mid-term examination next week!!
•Date : 4/3 (Mon) 16:00-17:40
•The test includes calculation problem. Thus, you had better bring calculator.
•You can answer by both English and Chinese. But, I recommend you to write in English (It is
very kind to me!). But, even if you answer by Chinese, it does not affect your score.
•You can bring anything for the test (e.g. PC, books)

Report task2
(Question 1) : The sun has a temperature of 5700 K and its radius is .
By using Stefan-Boltzmann’s law , please calculate the
luminosity of the sun
6.96 × 108
[m]
F = σT4
[W ⋅ m−2]
L[W]
(Question 2) : By including following keywords, please explain Hubble's law.
[keywords] spectroscopy, Doppler effect, velocity, galaxy, expansion
(Question 3) : Please choose one telescope below and explain the telescope’s scientific
achievement.
σ = 5.67 × 10−8
W ⋅ m−2 ⋅ K4
•Subaru telescope •ALMA telescope •FAST telescope

•Please send your report to shimabukuro@ynu.edu.cn by PDF.
Report task
Please including following information
1. The tittle of your email is “现代天⽂学作业报告”
2. Your name (姓名)
3. Your student number（学号）
Deadline of the submission: 2023/4/17 (Monday)
I accept the report written by English or Chinese, but I recommend you to write the report by
English (and it is very helpful for me!). Even if your English is wrong, it does not affect your
score.