Formation of the Solar System
As we have seen, the comets. asteroids. and meteorites are surviving remnants from the processes that formed the solar system. The planets, moons, and the Sun, of course, also are the products of the formation process, although the material in them has undergone a wide range of changes. We are now ready to put together the information from all these objects to discuss what is known about the origin of the solar system.
There are certain basic properties of the planetary system that any theory of its formation must explain. These may be summarized under three categories: motion constraints, chemical constraints, and age constraints. We call them constraints because they place restrictions on our theories; unless a theory can explain the observed facts, it will not survive in the competitive marketplace of ideas that characterizes the endeavor of science. Let’s take a look at these constraints one by one.
There are many regularities to the motions in the solar system. We saw that the planets all revolve around the Sun in the same direction and approximately in the plane of the Sun’s own rotation. In addition, most of the planets rotate in the same direction as they revolve, and most of the moons also move in counterclockwise orbits (when seen from the north). With the exception of the comets and other trans-neptunian objects, the motions of the system members define a disk or Frisbee shape. Nevertheless, a full theory must also be prepared to deal with the exceptions to these trends, such as the retrograde rotation (not revolution) of Venus.
In the realm of chemistry, we saw that Jupiter and Saturn have approximately the same composition—dominated by hydrogen and helium. These are the two largest planets, with sufficient gravity to hold on to any gas present when and where they formed; thus, we might expect them to be representative of the original material out of which the solar system formed. Each of the other members of the planetary system is, to some degree, lacking in the light elements. A careful examination of the composition of solid solar-system objects shows a striking progression from the metal-rich inner planets, through those made predominantly of rocky materials, out to objects with ice-dominated compositions in the outer solar system. The comets in the Oort Cloud and the trans-neptunian objects in the Kuiper belt are also icy objects, whereas the asteroids represent a transitional rocky composition with abundant dark, carbon-rich material.
As we saw in Other Worlds: An Introduction to the Solar System, this general chemical pattern can be interpreted as a temperature sequence: hot near the Sun and cooler as we move outward. The inner parts of the system are generally missing those materials that could not condense (form a solid) at the high temperatures found near the Sun. However, there are (again) important exceptions to the general pattern. For example, it is difficult to explain the presence of water on Earth and Mars if these planets formed in a region where the temperature was too hot for ice to condense, unless the ice or water was brought in later from cooler regions. The extreme example is the observation that there are polar deposits of ice on both Mercury and the Moon; these are almost certainly formed and maintained by occasional comet impacts.
As far as age is concerned, we discussed that radioactive dating demonstrates that some rocks on the surface of Earth have been present for at least 3.8 billion years, and that certain lunar samples are 4.4 billion years old. The primitive meteorites all have radioactive ages near 4.5 billion years. The age of these unaltered building blocks is considered the age of the planetary system. The similarity of the measured ages tells us that planets formed and their crusts cooled within a few tens of millions of years (at most) of the beginning of the solar system. Further, detailed examination of primitive meteorites indicates that they are made primarily from material that condensed or coagulated out of a hot gas; few identifiable fragments appear to have survived from before this hot-vapor stage 4.5 billion years ago.
The Solar Nebula
All the foregoing constraints are consistent with the general idea, introduced in Other Worlds: An Introduction to the Solar System, that the solar system formed 4.5 billion years ago out of a rotating Cloud of vapor and dust—which we call the solar nebula —with an initial composition similar to that of the Sun today. As the solar nebula collapsed under its own gravity, material fell toward the center, where things became more and more concentrated and hot. Increasing temperatures in the shrinking nebula vaporized most of the solid material that was originally present.
At the same time, the collapsing nebula began to rotate faster through the conservation of angular momentum (see the Orbits and Gravity and Earth, Moon, and Sky chapters). Like a figure skater pulling her arms in to spin faster, the shrinking Cloud spun more quickly as time went on. Now, think about how a round object spins. Close to the poles, the spin rate is slow, and it gets faster as you get closer to the equator. In the same way, near the poles of the nebula, where orbits were slow, the nebular material fell directly into the center. Faster moving material, on the other hand, collapsed into a flat disk revolving around the central object (Figure 14.11). The existence of this disk-shaped rotating nebula explains the primary motions in the solar system that we discussed in the previous section. And since they formed from a rotating disk, the planets all orbit the same way.
Figure 14.11 Steps in Forming the Solar System. This illustration shows the steps in the formation of the solar system from the solar nebula. As the nebula shrinks, its rotation causes it to flatten into a disk. Much of the material is concentrated in the hot center, which will ultimately become a star. Away from the center, solid particles can condense as the nebula cools, giving rise to planetesimals, the building blocks of the planets and moons.
Picture the solar nebula at the end of the collapse phase, when it was at its hottest. With no more gravitational energy (from material falling in) to heat it, most of the nebula began to cool. The material in the center, however, where it was hottest and most crowded, formed a star that maintained high temperatures in its immediate neighborhood by producing its own energy. Turbulent motions and magnetic fields within the disk can drain away angular momentum, robbing the disk material of some of its spin. This allowed some material to continue to fall into the growing star, while the rest of the disk gradually stabilized.
The temperature within the disk decreased with increasing distance from the Sun, much as the planets’ temperatures vary with position today. As the disk cooled, the gases interacted chemically to produce compounds; eventually these compounds condensed into liquid droplets or solid grains. This is similar to the process by which raindrops on Earth condense from moist air as it rises over a mountain.
Let’s look in more detail at how material condensed at different places in the maturing disk (Figure 14.12). The first materials to form solid grains were the metals and various rock-forming silicates. As the temperature dropped, these were joined throughout much of the solar nebula by sulfur compounds and by carbon- and water-rich silicates, such as those now found abundantly among the asteroids. However, in the inner parts of the disk, the temperature never dropped low enough for such materials as ice or carbonaceous organic compounds to condense, so they were lacking on the innermost planets.
Rotation of the Solar Nebula
We can use the concept of angular momentum to trace the evolution of the collapsing solar nebula. The angular momentum of an object is proportional to the square of its size (diameter) divided by its period of rotation ( D 2 P ) ( D 2 P ). If angular momentum is conserved, then any change in the size of a nebula must be compensated for by a proportional change in period, in order to keep D 2 P D 2 P constant. Suppose the solar nebula began with a diameter of 10,000 AU and a rotation period of 1 million years. What is its rotation period when it has shrunk to the size of Pluto’s orbit, which Appendix F tells us has a radius of about 40 AU?
Solution
We are given that the final diameter of the solar nebula is about 80 AU. Noting the initial state before the collapse and the final state at Pluto’s orbit, then
P final P initial = ( D final D initial ) 2 = ( 80 10,000 ) 2 = ( 0.008 ) 2 = 0.000064 P final P initial = ( D final D initial ) 2 = ( 80 10,000 ) 2 = ( 0.008 ) 2 = 0.000064
With Pinitial equal to 1,000,000 years, Pfinal, the new rotation period, is 64 years. This is a lot shorter than the actual time Pluto takes to go around the Sun, but it gives you a sense of the kind of speeding up the conservation of angular momentum can produce. As we noted earlier, other mechanisms helped the material in the disk lose angular momentum before the planets fully formed.
Check Your Learning
What would the rotation period of the nebula in our example be when it had shrunk to the size of Jupiter’s orbit?
Volt Solar Panels
A 12v solar panel generates enough voltage to charge a 12v battery. Solar panels that produce 12 or 24 volts of constant voltage is optimal for everyday household usage. However, solar panels that produce 24 volts are more expensive, and many consider buying solar panels of 12 volts.
In order to increase solar system power output without changing its voltage, 12v solar panels need to be connected in parallel.
12v solar panels connection
The wiring of several solar panels to each other can be performed in a few different ways depending on your situation.
Solar panels are connected in parallel using special equipment: branch connectors and a combiner box. All negative terminals are connected to one connector and all positive terminals are connected to the other connector.
With this connection, the voltage of every solar panel stays the same. The amperage from all panels adds up. This type of connection allows to increase the amperage of the whole solar power system without raising the voltage.
When connecting solar panels in series, the negative terminal of the first solar panel is connected to the positive terminal of the next solar panel, and so on.
With this type of wiring, the voltage of all panels adds up. The amperage of the system is equal to the amperage of the panel with the minimum amperage. For this reason, it is not recommended to connect solar panels with different values of the maximum current in series, since they will not work efficiently.
This type of connection combines the two previous ones. Applying this method of wiring solar panels allows for regulation of the voltage and amperage within the solar power system and its most optimal mode of operation.
In series-parallel connection, solar panels are connected in series and then combined in parallel.
How to choose the right 12v solar panel
As with any solar panel, there are a few important factors that need to be taken into consideration before buying a 12V solar panel.
- The efficiency of the solar panel
- Power tolerance
- Low-temperature coefficient and performance in low irradiance
- Warranty
- The type of solar cells
- Price
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Should I go for a 12V system or do I need a higher voltage system?
12 volt systems are the most popular option for solar installations due to its versatility.
RVs and motorhomes typically already have 12 volt batteries for lighting, hot water heater controls, AC/heating controls, and refrigerators. Therefore, it makes sense to use the voltage that already works for that system.
If your energy needs are around 1,000 to 5,000 watts, go for a 24 volt battery system.
24 volt systems are suitable for:
- 1. Large homes and apartment buildings
- 2. Commercial and industrial buildings
- 3. Parking structures
If your energy needs are over 3,000 watts, go for a 48 volt battery system. Large off-grid houses often use 48V.
What are the benefits of using 24v panels?
As mentioned, 24 volt panels are suitable for larger installations, One of the main benefits of using a larger voltage system is that an increase in voltage causes a reduction in the current flowing through it. This means you can use thinner cables for the same amount of power, which leads to a much lower wiring cost.
You can also typically see better inverter efficiency and regulation with higher voltage systems because an inverter doesn’t have to work quite as hard to keep its output constant.
How do I determine compatibility of components in a 12V or 24v system?
If you purchase a 12v solar panel you should pair it with a 12v battery (a 12 volt lithium battery will work best with the 12 volt solar panels), a 12v inverter, and at least a 12v charge controller. A 24v solar panel should be used with a 24v battery bank, 24v inverter, and at least a 24v charge controller. A 24v battery is not available, so you’ll have to connect two 12v batteries in a series connection in a battery bank.
It’s also very important that your solar panel’s rating is not higher than that of charge controllers, so be sure to check your charge controllers list of specifications. If you had 12 volt solar panels and your amps are 14, you would need a charge controller that had at least 14 amps. However due to environmental factors, you need to factor in an additional 25%. This brings the minimum amps that this charger controller must have to 17.5 amps. In this example, you would need a 12 volt, 20 amp charge controller.
How do I know what my energy needs are?
It’s incredibly important to properly size your solar installation. To determine what size system will best fit your needs, we recommend using the Renogy solar panel calculator. The solar sizing calculator allows you to input information about your lifestyle and appliances used to help you decide on your solar panel requirements. The solar panel calculator will then be able to tell you the minimum and recommended system size, as well as the recommended battery output.
If you have a 200ah battery, only 80% of that is usable due to depletion limitations, so you actually only have 160 amp-hours of energy to draw on. If you know that you typically can last two days with energy from that battery, that means you consume 80 amp hours a day.
Let’s say that you have a 100 watt 12 volt panel that will produce an average of about 30 amp-hours per day (based on an average sunny day). This means you would need three 100 watt solar panels or one 300 watt 12 volt panel to fully recharge your battery on the average day.
Built to last, charge after charge.
Weighing in at 22 lbs, the Lion 100W 12V solar panel makes for an easy choice to extent your camping trip a few more days because you now have the power you need. These panels are perfect to power the Safari LT, giving you power where you need it – tailgating, construction site, camping, or whatever situation you’re in. You can bundle and save more when you purchase one of our kits. Click here to see our kits
Weight (pounds)
Dimensions. Inches (L x W x H)
26.5 x 40 x 1 (Unfolded), 26.5 x 20 x 1 (folded)
Rated Power
Life Cycles
Short-Circuit Current (ISC) / Open-Circuit Voltage (VOC)
Maximum Power Point Current (Impp) / Maximm Power Point Voltage (Vmpp)
What is the warranty on it?
How long should the panel charge last?
It has a 20-year life expectancy.
The Lion 100W 12V solar panels uses monocrystalline cells.
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Lion 100W 12V Solar Panel
This purchase was actually an addition to the two sets of solar panels I already have. Easy to set up and use. Also the Technical advisor was helpful in making sure I got the right voltage (12v) for my system.
Lion Energy
Thank you for your purchase. and your great review!
Stellar product and service
The product was as described well built and works as expected.
solar panel
The shipping was quick and arrived intact. So far seems like it will do the job of collecting energy will last.
Great Company with great customer service
I ordered the Lion 100 12v solar panels and they arrived within 3 days! The solar panel came with an awesome solar protective travel cover which is awesome! I called LionEnergy to inquire if I could purchase another Solar panel cover to use with the solar panels I received with my 4patriots bundle. Customer Service was great and said they would send out a cover right away for free, no need to pay anything! I plan on purchasing more from this company, great customer service and their products are outstanding! Thank you!
Solar panels
This was easy to order, and arrived on time
Easy solar
Works great I hook it up to another one so I have double of whatever the sun is given. hooked up to the safari 500
solar panel
I like the 100 w 12 volt solar panel. I have three I use on my system. I will probably get a fourth. I just wish I had known it couldn’t be used on a 24 volt battery storage but I think I have figured out a workaround on that. thanks keep up the good work
A replacement I’m not mad to buy
Unfortunately the panels do not hold up to a 3/4 ton pickup rolling over them, but when you know how well these work you can’t do without them! Had to buy as a replacement, and I love how well they function! A must-have
Be prepared
Great! It is good investment in the event of an emergency.
Love this company!
Firstoff, the are very reasonable compared to most! I ordered two 100 watt solar panels to augment my array. Panels shipped same day. Delayed 2 days in final delivery because of weather but no bigggy. Came in sturdy outer cartons and i really like the included storage bags they came in. Great bonus, and thank you for that!! I got a feeling that rolling blackouts and power outages are going to become an issue here in America soon with these current bozos at the helm. These extra 2 panels will both speed up recharge on my solar generator AND make it drain considerably slower when operated with panels active. Next purchase from Lion will be 2 more Anderson cords to extend the distance from panels to genny. The solar genny is a household secondary unit for mostly indoor things like computers and accessories to work from home, Keurig coffee maker, oil filled radiator heaters, nebulizer unit, cable box, TV, DVD player, portable cooking burners, etc. I have a 10,000 watt gas generator to handle the big stuff like the friges and freezers and window AC units with a boatload of stored treated gasoline that i rotate out every year. If we run out of gas, the solar becomes primary. The 2 new panels from Lion will definitely help to maximize our access to power if it ever comes to that. You can never put a price on peace of mind!!
Mobility
The Solar Panel is easy to place and relocate. The carrying case protects the panel when in storage,
Hello, I like how the solar panels work with the generator, Is there a way I can help sell them?
This product is saving me
I’m on disability income and can’t afford expensive energy bills. So, I purchased Lion’s Emergency Preparedness Kit in the Spring which included the Safari LT solar generator and a 100W solar panel to which I added a 2nd 100W solar panel, a 25′ extension cable and Safari UT 700 battery. I used these products for 6 months to power my 100W widescreen TV and my computer (75W average) which has brought me from paying more than a similar home in my area as reported by my electricity provider to paying 7 less (7.50 less monthly on average than last year and even with a hotter summer this year with a higher air conditioner usage). Because it’s getting cloudier, and wanting a shorting charging time, I purchased this 3rd 100W solar panel. This product is working as well as the previous 2 and I’m very happy with the performance. The only con I have found is that the outer insulation pulls away from the connector, the pins can come out of the connectors and one of the connectors has broken (part of the plastic surrounding the pin) but is still usable and the pins can be reseated into the plastic connectors. Admittedly, I accidentally pulled them too hard while moving the panels so it’s my own fault but I believe the cables could be reinforced better at the connectors to prevent these issues.
Jupiter’s moon Io
The next item on the solar system brightness list is Jupiter’s volcanic satellite, Io. At a little larger than our moon, Io is the innermost Galilean satellite and shines at magnitude 5.0 when it’s at its best.
Can you see Io – or Ganymede – with the eye alone? In theory, you should be able to. But in practice they’re not that easy to see in the glare from Jupiter itself. Some observers with renowned vision (for example, Steven James O’Meara) have claimed to have seen Ganymede with the unaided eye. But you’ll likely need binoculars for Ganymede or Io, or Europa (see below). Small telescopes show all four Galilean moons in their never-ending dance around Jupiter.
Asteroid Vesta
The fourth asteroid discovered, Vesta, is the only asteroid to make our list of brightest solar system objects. Vesta is the 2nd-largest asteroid after Ceres. Vesta can reach magnitude 5.1 at its closest approach to Earth. Its next opposition – a highlight of the year for asteroid observers – is on December 21, 2023.
During Vesta’s opposition, Earth will sweep more or less between Vesta and the sun, bringing the asteroid closest to us for the year. Because Vesta doesn’t have a bright nearby locator, as Ganymede and Io have with Jupiter, it’s best to watch for Vesta for a couple of nights in a row to see which dim “star” in the area appears to move slowly in front of the fixed star background. Visit In-The-Sky.org for more.
Jupiter’s moon Europa
We bounce back out to Jupiter for the next item on the list, Europa, another of Jupiter’s four large Galilean moons. Europa is a great object to attempt to view and ruminate on, because it may harbor an ocean – and possibly life – beneath its icy crust. Europa just makes our list of the brightest objects in the solar system at magnitude 5.2. Again, we recommend using observing software, such as SkyandTelescope.com’s interactive Jupiter moon page, to know which Galilean moon is which.
Finally! Many know that planet Uranus is theoretically visible to the unaided eye. The 7th planet from the sun appears at magnitude 5.6 at its best. Uranus is most easily picked up with the unaided eye after first pinning down its location with binoculars or a telescope. It has a disk instead of a pinpoint image through an optical device and may even appear faintly bluish green. It is particularly easy to find on the occasions that it pairs up closely with objects easier to locate, such as Mars.
Bottom line: Here are the top 12 brightest natural solar system objects, in order from brightest to dimmest. If you’ve seen every one of these objects, with or without optical aid, congrats!