Astronomy Unit 3: Solar system
In composition, asteroids and meteroroids are most like....
Terrestrial planets
What are terrestrial planets?
Terrestrial planets are planets composed of rock and metal, and perhaps even dust bits and have and actual surface that a spacecraft can land on. In our solar system, the terrestrial planets are those 4 closest to the Sun: Mercury, Venus, Earth, and Mars.
Inferior Conjunction
When a planet is between the earth and the sun
Superior Conjunction
When the sun is between the earth and the planet
the smallest sort of interplanetary matter is called...
interplanetary dust
Smaller silicate/metal/carbon based objects that STRIKE the Earth are
meteorites (Ites, bites the floor)
What theory best describes the formation of our solar system?
nebular theory: "The Nebular Theory would have started with a cloud of gas and dust, most likely left over from a previous supernova. The nebula started to collapse and condense; this collapsing process continued for some time. The Sun-to-be collected most of the mass in the nebula's center, forming a Protostar . A protostar is an object in which no nuclear fusion has occurred, unlike a star that is undergoing nuclear fusion. A protostar becomes a star when nuclear fusion begins. Most likely the next step was that the nebula flattened into a disk called the Protoplanetary Disk ; planets eventually formed from and in this disk. Three processes occurred with the nebular collapse: Temperatures continued to increase The solar nebula spun faster and faster The solar nebula disk flattened The orderly motions of the solar system today are a direct result of the solar system's beginnings in a spinning, flattened cloud of gas and dust." --- https://courses.lumenlearning.com/atd-fscj-introastronomy/chapter/the-nebular-theory/
Where did most of the material for our solar system end up and how much?
99% of the matter in the nebula went into forming the Sun, which is composed of Hydrogen and hydrogen plasma, that then forms Helium. The leftover was, again, mostly Hydrogen, Helium, and Ice particles, which condensed to form the Jovian planets, which is why they are so big. Since there was a very minimal amount of rock and metal(heavier elements that arrived from faraway supernova explosion), the smaller planets are composed of that matter.
The relatively dark and smooth part of the moon is called...
the maria, sea of baltic ash
Characteristics of terrestal planets
-close to sun -solid surface - small masses
What are characteristics of Jovian planets?
- having rings - large and gaseous - having long orbital periods
A meteorite is...
A chunk of space debris that has struck the ground
Why does a comet's tail ALWAYS pointed away from the sun?
A comet's tail always points away from the Sun because the gas tail's molecules emitted by the comet get ionized by the sun's light and solar winds. The tail loses electrons, which become charged, and is thus highly susceptible to magnetic fields.
What is the difference b/t meteorite, meteoroid and meteor?
A meteorite is are meteors that passed through the sun's atmosphere, didn't burn up in the process, and landed on Earth. A meteoroid is a meteor who entered the Earth's atmosphere and burned up in the process, but did not land on the floor. A meteor is a much smaller version of an asteroid floating through space and orbiting around the Sun.
Explain the process of how the solar system was formed.
A nebula(a cloud of gas and dust) started to spin and condense the material in its center. As the material condensed, the same amount of energy was now concentrated in a smaller space. To keep up with the law of conservation of Angular Momentum, the nebula began to contract at a greater speed, thus beginning its own collapse under its own gravity. Soon, a dense cloud of matter formed in the center, a Protostar, and as the nebula continued to spin and condense, nuclear fusion was initiated, becoming a full-fledged star. However, some material was still left over, and because supernova(a death of another star) brought heavier elements, these leftovers began to form a protoplanetary disk. In this protoplanetary disk, planetisimals collided to form protoplanets and then planets.
What is accretion disk?
A rotating disk of matter, such as dust and gas particles and planetisimals, formed by accretion formed around anything with significant enough gravity. This process is aided by the law of conservation of angular momentum, and as more mass is accumulated, the accretion disk spins faster and faster and the center has more gravity.
Define solar system.
A solar system is a collection of planets and other celestial bodies around a star. In our case, the solar system is the collection of 8 planets around our Sun; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
What does albedo mean? Which would have a higher albedo, a car or a rock?
Albedo is the measure/level of reflectivity of all objects in space. A car would have more reflectivity, as sometimes you can see the flash of the reflection of a car passing by through a window while a rock seems to absorb light.
What is an exoplanet? How are exoplanets located in our galaxy?
An exoplanet is a planet outside of this solar system. There are around 100 thousand million exoplanets in the milky way.
Explain why Venus is so bright in the night sky.
As Venus had a runaway greenhouse effect, Venus' atmosphere is composed of thick, white clouds that thus reflects almost all of the sunlight that falls on it, thus being so bright in the night sky.
What is the difference b/t asteroids and meteoroids?
Asteroids are much larger than meteoroids but are made of essentially the same material. Asteroids are separated into 3 groups: those in the asteroid belt, those that still orbit the sun but are not in the belt, and those that still orbit the Sun but have the potential to land on Earth. Asteroids are composed of carbon, Iron and Nickel, or silicate rock. Meteoroids are much smaller and burn up completely in the Earth's atmosphere upon entrance. Meteoroids are either stony, iron, or stony iron.
The tail of a comet always points....
Away from the sun
Why is Venus the second brightest object in our night sky?
Because it reflects most of the light that strikes it
Which objects have been LEAST modified since the formation of the solar system?
Comets
Which of the following has an icy composition?
Comets
Why would mars ever appear to change color?
Dust storms
n what plane did all the planets form on?
Ecliptic
Planetary orbits are what?
Elliptical with varying eccentricities
Name the Jovian (Gas) planets in order. How many moons does Jupiter have?
From asteroid belt: Jupiter, Saturn, Uranus, and Neptune. Jupiter has 79 confirmed moons.
List the planets in order.
From the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
What gasses are found in the atmosphere of Jovian planets?
Helium and Hydrogen
Which planet has the most natural satellites?
Jupiter
Jovian Planets:
Jupiter, Saturn, Uranus, Neptune _ JSUN
Explain why Mars look red from Earth?
Mars looks red from Earth as its surface contains a lot of iron metals that have oxidized and rusted, creating a rusty red color. This oxidation could be the result of water that once was on its surface or any oxygen that existed in the atmosphere a long time ago. The iron could have also oxidized from the constant sunlight exposure that broke down the gases in the atmosphere to push out oxygen. However the process was, Mars appears red from Earth due to the iron oxide.
Explain why Mercury has extreme temperatures compared to other planets?
Mercury is the closest planet to the sun, and thus has no atmosphere, only an exosphere. Therefore, Mercury is vulnerable to chaotic sun events. When the sun's flares occur or when mercury is facing towards the sun, there is no atmosphere to regulate the temperature and Mercury is extremely hot. However, when Mercury is facing away from the sun, the temperatures are extremely low.
From what do most solar systems form?
Most solar systems form from a nebula condensing and a supernova explosion, as this creates the star in the middle and the celestial bodies orbiting around.
Do the planets revolve at the same rate? What is your proof?
No. Each planet completes its orbit in contrasting time lengths. For example, Mercury, the smallest planet, has a period of 88.695 Earth days while, say, the Jovian planet Saturn has a period 30 times that of 29.745 years.
How does our moon compare in size to other moon in our system? What is the biggest moon? Who has the most?
Our moon is on the smaller side in comparison to other moons in our solar system, but it is definitely not the smallest. The biggest moon in the solar system is Ganymede, one of Jupiter's Galilean moons, which is bigger than Mercury itself. Jupiter has the most moons out of the rest of the planets in the solar system.
What do we know about our solar system and its creation, spacing, planets/body composition and age?
Our solar system is 4.5 billion years old. It was created from a nebula and a supernova helped the creation of planets by sending in heavier materials through a shockwave. The planets closest to the Sun are the terrestrial planets, as rock and metal were the only materials able to condense at that proximity and temperature. The outer planets are composed of gases and ice and dust particles because it was finally cold enough for that material to condense. 99% of the nebula material went into forming the sun. Mention protostar, accretion disk, planetisimals, protoplanets, and planets. Mention that asteroid belt, comets, meteors, nuclear fusion, why planets formed where they did and why those planets are more/less dense, law of conservation of angular momentum
Our solar system is made of interplanetary dust. Explain.
Our solar system is made of interplanetary dust as when the nebula was condensing, the sun's birth and initiation of nuclear fusion was triggered by the shock of a big star faraway exploding and essentially launching the materials into other nebulas. Thus, our very sun has material from a dead star, and the planets themselves are composed of heavier elements that only arrived here from the supernova.
Where is the Kuier Belt found in the solar system?
Past neptune
The apparent reversal of a planet's motion is called....
Retrograde Motion
Define retrograde motion. Why does it happen?
Retrograde motion is the optical illusion of when planets appear to move in reverse direction. In reality, Earth(or any planet in an example) is just moving faster than a slower planet and gives the appearance of retrograde motion(going forward, backward, and then forward again).
What three types of materials make-up meteors/asteroids?
See response for question 20.
The stream of energetic, charged particles that flows outward from the Sun is called the _____.
Solar wind
Discuss solar wind from flare to Earth.
Solar winds occur nonstop due to the sun's constantly expanding corona while solar flares occur every 11 years due to its cycle. Solar winds are also moreover more peaceful, and are a radial flow of particles(mostly protons and neutrons) emitted from the Sun. On the other hand, solar flares are quite violent outbursts on the Sun's surface. Overall, both the timing and intensity of the solar wind and solar flares differ.
Describe the makeup of most of the gas giants (Jovian Planets).
The Jovian planets are comprised of mostly Helium and Hydrogen with trace gases like methane, sulfur, ammonia, water vapor, and ice and dust particles. The cores are mostly solid metal/rock, as the very high pressures have compressed the core to a hard solid.
What is the difference b/t the asteroid belt, Kuiper Belt and Oort cloud?
The asteroid belt is located between Mars and Jupiter and is only host to asteroids composed of rock and metal. The Kuiper belt is located right outside of Neptune and has objects composed largely of ice, methane, and ammonia particles, like short term comets, icy rocks, and dwarf planets like Pluto. The Oort cloud is located way beyond the Kuiper belt and ends at the edge of the solar system. The Oort cloud is a spherical ball surrounding the solar system with unknown icy objects, and whatever ice balls are ejected from the Oort cloud become long-term comets.
What is true of the densities in our solar system?
The denser planets are closer to the Sun
Which planet is the least dense in our solar system? The most?
The least dense planet in our solar system is Saturn. The most dense planet is Earth.
What are the criteria for a planet to be a "planet"?
There are three rules sustained worldwide for planet classification: 1- It must orbit around the Sun. 2- It must have sufficient mass to create enough gravity to create hydrostatic equilibrium and be somewhat round(i.e. Earth bulges at the center and is not a perfect sphere) 3- It has to create enough gravity to clear out neighborhood around its orbit.
Why do all the true planets appear to be on the same plane?
They formed on the same accretion disk.
The difference between an asteroid and a meteoroid is the object's....
size
