Sunspots are areas of the sun that appear dark because they are cooler than their surroundings and are used as an indicator of solar activity. They are formed because material at the solar equator moves significantly faster than the materials at the poles, causing the magnetic field lines to become warped. If the magnetic field is twisted enough, the stream of flowing current may make a “rope of magnetism”, some of which may break through the visible layer, looking like two sun spots.
Solar maximum is characterized by a lot of solar activity and the greatest number of sunspots, and solar minimum is characterized by low solar activity and a small number of sun spots.
follows an 11-year cycle, shifting from maximum to minimum and can be tracked by NASA’s Solar Dynamics Observatory Spacecraft. In early 2017, there was a 15-day stretch where no sunspots were visible, which could be a clue that the sun is entering a lull in activity, the longest since 2010. The predicted solar minimum is coming up between 2019 and 2020.
The National Aeronautics and Space Administration (NASA) is known throughout the world as an organization whose focus in on what lies beyond Earth. A lesser-known NASA department, Applied Sciences, is an example of the opposite. Applied Sciences diverts resources and minds towards using satellite and aeronautical engineering for the Earth Sciences. Applied science measures air quality, water quality, geothermal quality, CO2 concentrations, and a number of other geological and climate-related issues. One mission, in particular, distributes air quality data openly and freely to the public, allowing people to better understand their local environment and any potential risks. It also allows engineers to understand the consequences of their emissions or renewable technologies. Another project analyzes clouds and what that can say about surrounding mountains or precipitation in that area (in ways that liquid water analysis can’t).
Voyager 1 is currently the farthest spacecraft we have ever sent out. It was launched in 1977 and is currently 141 AU or 13 billion miles away from Earth right now. It is traveling at 38,000 mph but has not even travel a full light day yet. The original purpose of the Voyager missions was to study Jupiter, Saturn, Saturn’s rings, and the moons of each planet more in depth. The first stop on Voyager’s mission was Jupiter. When passing by this giant, the satellite had captured images of Jupiter’s moon, Io. On Io the most startling discovery by far was that there was active vulcanism occurring. This could mean there’s a potential of a slight atmosphere, that there’s a molten core, and maybe there’s even a possibility of life. The activeness of these volcanoes were incredible, as the plumes extended up to 300km above the surface. Another moon that Voyager was able to capture was Europa, by far the most exciting moon in the solar system. “There is a possibility that Europa may be internally active due to tidal heating at a level one-tenth or less than that of Io. Europa is thought to have a thin crust (less than 30 kilometers or 18 miles thick) of water ice, possibly floating on a 50-kilometer-deep (30-mile) ocean.”, according to NASA’s Voyager website . In addition, Voyager found out about Jupiter and Saturn itself. It was able to retrieve information about the Red Spot on Jupiter, and how its storm goes counterclockwise instead of clockwise like storms do on Earth. It was able to find out the composition of Saturn’s rings as well. Hopefully NASA will continue to send missions like this for us to learn about our solar system and its planets.
Martian dust devils are much like tornadoes on Earth. Both storms form the same way, but what distinguishes these dust devils from the tornadoes on Earth is that they are much bigger ( 1-2 km across and 8-10 km wide!) and the fact that dust devils occur much more frequently on Mars than tornadoes do on Earth. Although the exact frequency is not known, during the summer and spring months on Mars, around half a dozen dust devils can be spotted each day. This is due to the extreme variance in temperatures on Mars between daytime (where it reaches 20 degrees Celsius) and nighttime (which cools to around -90 degrees Celsius). Because of the varying temperature, the ground becomes hotter than the air above it and the heated air near the ground rises as the cooler air begins to fall. This coupled with a horizontal wind forms the vertical columns which forms the beginning of a dust devil. Despite the fact that dust devils are much bigger than tornadoes, because of Mars’s lower atmospheric pressure, the winds from the dust devils would be bearable to a person standing in one, but the high speed at which the sand is being moved would be much more dangerous.
Martian dust devils are much like tornadoes on Earth. Both storms form the same way, but what distinguishes these dust devils from the tornadoes on Earth is that they are much bigger ( 1-2 km across and 8-10 km wide!) and the fact that dust devils occur much more frequently on Mars than tornadoes do on Earth. Although the exact frequency is not known, during the summer and spring months on Mars, around half a dozen dust devils can be spotted each day. This is due to the extreme variance in temperatures on Mars between daytime (where it reaches 20 degrees Celsius) and nighttime (which cools to around -90 degrees Celsius). Because of the varying temperature, the ground becomes hotter than the air above it and the heated air near the ground rises as the cooler air begins to fall. This coupled with a horizontal wind forms the vertical columns which forms the beginning of a dust devil. Despite the fact that dust devils are much bigger than tornadoes, because of Mars’s lower atmospheric pressure, the winds from the dust devils would be bearable to a person standing in one, but the high speed at which the sand is being moved would be much more dangerous.
August 20, 1977. The flyby-type probe Voyager 2 was launched from Earth, destined to explore our Solar System and beyond. Passing by Jupiter, Saturn, Uranus, and Neptune, Voyager 2 carried with it instruments to relay close-up images of these Jovian planets, and a message from Earth to be read and listened to by those who may receive the probe far in the future after it departs from our Solar System. These messages are carried by a golden record – the golden record – inscribed with sounds from our planet including greetings in fifty-five human languages in addition to a whale greeting, and images and music from different cultures. Etched onto the protective cover is a symbolic representation of instructions depicting how to use the included equipment to play the record as well as images explaining where the probe originated by means of a pulsar map (lower left of record) that shows the Sun’s location relative to the fourteen nearest pulsars to Earth.
Two twins. Exploring where no other spacecraft has ever explored before. This was the goal that NASA set out to accomplish when they launched the Voyager spacecrafts. At least, this is what their missions came to be. However, it is not just the missions themselves that make them famous, but also what they carry for humanity. However, let us not get ahead of ourselves without a bit of history.
The Voyager 1 and Voyager 2 were sent into space by NASA in 1977 from Cape Canaveral, FL, in order to survey Jupiter, Saturn, Saturn’s rings, and large moons that surround the two planets. Voyagers 1 and 2 were sent 16 days apart from each other, and were only built to last 5 years. However, the technology proved resilient in space, and today the Voyager spacecrafts still report back to mission control.
Voyager 1 on left; Voyager 2 on right. Image sourced from annesastronomynews
When it was found that the Voyager spacecrafts could continue doing research, NASA made the decision to direct the spacecraft’s resources to two locations. Voyager 1 was to be sent deep into interstellar space, and so from the end of its original mission the probe has been travelling deep into space. On August 25, 2012, it escaped the solar system and officially hit interstellar space. Voyager 2, on the other hand, was to be used to survey Neptune and Uranus, and is still the only man-made object to date to survey the two ice planets. Now all of this information is nice and dandy, but it leads to an important premise.
Before the Voyager spacecrafts were sent, a decision was made to include some information about humanity on the spacecrafts, just in case alien life happened to stumble upon it. This culminated in the creation of a golden record. Two copies of the record were made for each one of the Voyagers, but their contents are what continue to intrigue those that look into the topic.
On the front side of the record, seen as the left side of the featured image, are a variety of images etched into the golden surface. The images are supposed to depict the origin of the spacecraft as well as how the record is to be played. On the backside of the record are 115 images encoded in analogue that are supposed to represent Earth and human life. The rest of the record contains greetings and language starting with the Sumerian language (spoken 6000 years ago) to greetings today. Beyond that, it also includes 90 minutes of music hand selected from a variety of genres, both classical and modern to the time. It would intrigue some of you to know that the music, greetings, and images were selected by a committee at NASA headed by the famous physicist Carl Sagan.
So, what does this mean to you? Should we be afraid of broadcasting ourselves to alien civilizations? Stephen Hawking says yes, but others argue that it is important to learn about the rest of our universe. When selecting these images and sounds, Sagan and his team sought to reflect every facet of human life. So, some images are happy, sad, strange, and even anatomical. As a man of science, Sagan made sure to include a representation of the hydrogen atom and the makeup of the DNA molecule, two of the most profound discoveries in science. I have went ahead and placed an image below, but you can view all 115 at the Voyager website.
One of the more interesting photos encoded in these disks. Sourced from NASA
It may be the case that these spacecrafts are never found. That they will live out the rest of their existence floating in space, just like any other asteroid, or planet, or solar system, or even galaxy. But on the off-chance that another being does see it, we give a signal of hope. A hope that we are not alone in the universe. A hope that there is something more beyond us, and something more beyond them. Today, Voyager 1 travels alone in deep interstellar space, doing what it was meant to do. But, in doing this, it remains alone in the vastness of space. One day, its battery will have no power left to run its critical processes and Voyager 1 will simply float in space, carrying a bit of humanity with it. I think that, for a moment, we all feel like Voyager 1. Let this piece, selected by Sagan, resonate as we think about the loneliness of being a single spec of humanity within a sea of other worlds.
The nuclear energy can be generated in two ways – fusion and fission. Both fusion and fission energy are generated by altering atoms. What is the difference between fusion and fission? And which way will generate more energy?
As the word “fission” means separate a thing into different parts, nuclear fission means releases energy by splitting atoms. Nuclear fission happens when an unstable isotope is contacted by some high-speed particles. At this time, the unstable isotope is accelerated and then break into small particles.
Unlike “fission”, nuclear fusion means “fusing” several particles into “one”. Nuclear fusion happens when several low-mass particles compress together and release the neutron they do not need anymore. By uniting different particles and releasing neutron, a huge amount of energy is released.
Although nuclear fission can generate higher energy than nuclear fusion, we can hardly found any nuclear fission in our sun. The reason is that nuclear fission requires a particle with enough mass so that it can be “split” into several particles. However, the major element inside Sun are Hydrogen and Helium, which are both low-mass particles. Therefore, the major nuclear energy inside the sun is generated by nuclear fusion.
Today we hear about climate change pretty often. Whether it’s politicians debating on policy or the “please recycle” signs on the backs of plastic products, the reality of pollution and the other bad ways humans have influenced the environment is hard to ignore. CO2 emissions and the greenhouse effect are common themes in this topic, since they pose the most devastating yet entirely feasible threat to life on earth. From the many angles that one can look at pollution and climate change, whether that’s from politics, climate science, or anthropology, or marine biology, one of the most informative angles come from the astronomical perspective.
The reason to be so concerned about carbon dioxide (CO2) emissions becomes undeniably clear when you compare the Earth to Venus. Just a little close to the sun, Venus is otherwise very similar to Earth in size and composition, yet it is completely uninhabitable. Although Venus has volcanoes and perhaps tectonic plates just like its sister, Earth, its mean surface temperature is a whopping 735 Kelvin! That’s 462 °C or 863 °F, much to hot for habitation. Why is Venus so hot? Its atmosphere is composed of 96% CO2, compared to the Earth’s almost complete lack of CO2 in its atmosphere. When an atmosphere has lots of CO2, then the Greenhouse Effect causes the planet to retain its heat and get hotter and hotter. So where is all the Earth’s CO2? Well, much of it is stored in the ground in places such as coal and oil, and as we burn them as sources of energy it could potentially put more CO2 into the atmosphere than the Earth could handle and snowball (no pun intended) out of control, causing its temperature to get higher and higher until it is uninhabitable. For the astronomer, then, caring about climate change and getting CO2 emissions under control is about keeping the Earth from ever looking like Venus, staying blue, white, and beautiful instead of a waterless wasteland.
Unfortunately, our Solar System will not exist forever–our Sun’s lifespan is indeed finite. Sunlike stars stay on the main sequence for approximately 10 billions years. In other words, this is about how long the Sun will shine. The Sun is about 4.6 billion years old, so we may expect about 5.4 billion more years of sunshine on Earth. But here’s the problem: as the Sun dies, it will catastrophically swell to a radius that will destroy most of its orbiting planets. In this so called “red giant phase”, all the hydrogen of the star has been fused to helium, and so heavier elements begin fusing in the core.
In this phase, the Sun will expand to achieve a radius of more than twice the distance between the Sun’s center and the Earth. In other words, our planet will be swallowed up by the Sun. Following this red giant phase, the Sun will shed its outer mass in a planetary nebula, leaving behind a small, superdense white dwarf (essentially the corpse of the star) at the center.
