Astrophysics Flashcards
Mercury
📍 1st Planet 🧀 Small with craters
📏 0.4 AU from the sun
⚪️ 1/3 Earth size
🕳️ Full of craters
☁️ No atmosphere
Venus
📍 2nd Planet HOT 🥵
📏 0.7 AU from the sun
⚪️ = Earth size
🔥 Super hot 460 C
☁️ x90 thicker atmosphere
Mars
📍 4th Planet - Sand, Rust & Ice
📏 1.5 AU from the sun
⚪️ = 1/2 Earth size
🧊 ICE. May have have been liquid before..
🔨 1/3 Gravity
Jupiter
📍 5th Planet - gas giant
📏 5.2 AU from the sun
⚪️ = More than 1,300 Earths would fit inside Jupiter. Core x
10 earth, the rest is gas
💨 Does not have a solid surface, made of hydrogen and helium like the sun ☀️
Saturn
📍 6th Planet - 💍 Rings & moons
📏 9.5 AU from the sun
⚪️ = Smaller than Jupiter
🪐 Gas giant with rings
🌚 🌝 🌙 Many moons (145!)
Uranus
📍 7th Planet - Smaller gas giant
📏 19.8 AU from the sun
⚪️ = Smaller than Saturn
💨 🧊 Gas & ice giant
Neptune
📍 8th Planet - Smaller gas giant
📏 30 AU from the sun
⚪️ = Smaller than Saturn
💨 🧊 Gas & ice giant of water, methane, and ammonia – above a small, rocky core.
Pluto
📍 9th and DISGRACED for being a MAVERICK 🤘🏻😑
📏 30-49 AU from the sun
⭕️ elliptical & tilted orbit
⚪️ = 1/6th of Earth
🧊 🪨 made of ice & rock
Object in Kuiper Belt
Asteroid Belt
💫 Between Mars & Jupiter
🌚 Ceres dwarf planet + asteroids
⭕️ Influenced by Jupiter, occasionally pushed inwards towards the sun, m collision risk with earth
Kuiper Belt
💫 Beyond Neptune
🧊 Icy bodies + Pluto 🤘🏻🌚
☀️ When they come in towards the inner solar system, they heat up to create gas-tailed comets 💫
Oort Cloud
💫 distant region almost half way to nearest star, containing potential comets
Solar System
☀️ Sun
⚪️ Mercury
🥵 Venus
🌍 Earth
🟠 Mars
🪨 Asteroid Belt & Ceres
🟡 Jupiter 💨
🪐 Saturn 💨
🔘 Uranus 💨
🔵 Neptune 💨
🤘🏻 Pluto
💫 Kuiper Belt
Hubble’s Law
Explains the expansion of the universe using three lines of evidence:
- By measuring distance between galaxies and speed of recession: approx 13.7 MA
- Cosmic microwave glow: 300,000 after big bang and still permeates the cosmos.
- Abundance of HELIUM: after big bang, nuclear fusion converting hydrogen atoms into helium. 1/10th of universe is helium.
BONUS: the darkness of the sky (there are not infinite stars, or the sky would be bright)
Dark Matter
🌚 The 96% of the universe that consists of unknown substances, humans have not identified.
Cosmic Microwave Background (CMB)
Cooled remnant of the first light that could ever travel freely throughout the Universe. This ‘fossil’ radiation, was released soon after the ‘Big Bang’.
It took about 300 000 years for the Universe to cool down to a temperature at which atoms can form (about 3000°C). Matter then became neutral, and allowed the light to travel freely: the Universe became transparent. The relic of that ‘first light’ is the CMB.
Antimatter
🕳️ the antiparticle with same mass but opposite charge of elementary particles:
- anti up-quark
- anti down-quark
- anti neutrino
When matter and antimatter come into contact, the annihilate each other transforming into pure energy according to Einstein’s E=mc2
Law of Special Relativity
E = mc2
Equivalence of course energy and matter, and they can be converted.
E = energy
m = mass
c2 = conversion
Elementary Particles
⚛️ the smallest known building blocks of the universe 🔴⚪️🔵⭕️🟢⚫️ we do not yet have sizes or measurements for these particles.
⚛️ ATOM : made up of elementary particles, enclosed in a nucleus (protons and neutrons) and on the outer shell (electrons)
⚡️ ELECTRON : elementary particle carrying a negative electric charge
🔴🔵 PROTONS & NEUTRONS : make up the atom’s nucleus. Made up of quarks.
➕➖ QUARKS: building blocks of protons and neutrons.
➕➕➖ UPquark
➖➖ DOWNquark
⚪️ NEUTRINO: free-roaming particle. Has no electrical charge. Everything emits neutrinos.
Laws of Physics
⚡️ ELECTROMAGNETIC FORCE : attraction and repulsion between positive and negative charges
💪🏻 STRONG FORCE : holds quarks together to form protons, neutrons and other particles
☀️ WEAK FORCE : radioactive decay and burning of the sun
☄️ GRAVITY : gravitational interaction between celestial bodies, and causing collisions towards large bodies
Higgs Field
The Higgs boson is the fundamental particle associated with the Higgs field, a field that gives mass to other fundamental particles such as electrons and quarks.
It is the energy of the vaccum, the medium that fills the space of the universe.
Supernova
💥 ✨ Colossal stars that emerged after the cosmic dark ages, exploded repeatedly to birth new stars, in a repeating cycle and scorching radiation that shaped their galaxies.
A dense cloud collapses, creating filaments that condense in hot, gaseous spheres which continue to heat up and enable nuclear fusion, turning hydrogen into helium, and then carbon and oxygen.
Smaller stars burn for much longer and end when they run out of hydrogen, whereas massive stars continue to contract and create more elements. Gravity is responsible for the death of stars when the force wins over a depletion of active fuel, triggering a cataclysmic supernova explosion, generating more elements - leaving behind a singularity (black hole).
All elements found on our planet (and the universe) were born from the depth of the stars.
Carl Sagan «we are made of starstuff» ✨
Singlularity
🕳️ The region of collapse of a star into a black hole, during a supernova cataclysmic event. Gravity is so strong - nothing (even light) can escape. The outer layers of the supernova leave behind a gas cloud visible for hundreds of years.
In our galaxy, there are 100 million black holes.
