This is a text widget, which allows you to add text or HTML to your sidebar. You can use them to display text, links, images, HTML, or a combination of these. Edit them in the Widget section of the Customizer.
In casual conversation, Mars is probably the planet that most people think of when they think of life existing on other planets. Part of the reason that we humans are able to exist here on Earth is because of the Earth’s atmosphere. This atmosphere is protected from things like solar winds by the network of magnetic fields that surround it. Mars, on the other hand, no longer has such strong magnetic field networks. However, during its early history when it was a much warmer planet, scientists believe that Mars did actually have a protective magnetosphere. Knowing this, it is interesting to consider the following: is it possible for Mars to regain such magnetic fields and subsequently develop a thicker atmosphere? According to James Green, director of NASA’s Planetary Science Division, the answer is yes, and it could be a relatively soon possibility with human intervention. What is most interesting about this is that if Mars had a functioning magnetosphere that protected against solar winds and a thicker atmosphere, the climate on the planet would be much more hospitable for human life. Greene poses an interesting mechanism for re-creating a magnetosphere on Mars: a magnetic shield. This may sound like something out of a science fiction movie, but, according to Greene, it basically consists of a large, closed electric circuit that could create an artificial magnetic field around Mars. The shield would function to protect Mars from solar winds, allowing Mars to build up an atmosphere, and create a warmer future for the planet. This kind of process of humans deliberately intervening in a planet in order to make it more hospitable to human life is called “terraforming” and remains a controversial topic. What do you guys think about humans taking such actions?
We only had to memorize a few dates for Astro 2110, but one of them was how long ago life on Earth began. Memorizing such dates are easy, but I think it’s so interesting to consider how exactly scientists (and our textbook authors!) are able to determine such dates and how new or improved evidence causes them to change over time. A recent study published in Nature by lead authors Matthew Dodd and Dominic Papineau offers an example of that.The study analyzed jasper rock samples from seafloor hydrothermal vent precipitates in Quebec, Canada and found microfossils containing evidence of bacteria that was at least 3.77 billion years old (they could be older). The microfossils are very small and invisible to the naked eye. The calculated minimum age of 3.77 billion years makes the fossils the oldest evidence of life on our planet (a 2016 study also published in Nature reported finding evidence of ancient life that was 3.7 billion years old). Although the discovery is exciting, there has been some debate about the fossil findings, especially as related to the exact age of the samples. If the finding is confirmed, however, it would be especially important for the field of astrobiology because it adequately connects the beginning of life to hydrothermal vents. Thus, research on life on other worlds like Mars could be based on a similar connection and on similar evidence.
The asteroid belt lies between Mars and Jupiter. This area is where the dwarf planet Ceres is located. Given that it was the first dwarf planet to be visited by a spacecraft and the largest object in the asteroid belt, there have been quite a few interesting discoveries about this celestial object. Here are a few:
Ceres actually makes up ¼ of the asteroid belt’s mass.
Ceres is about the same size as the state of Texas!
Like Pluto, Ceres has actually gone through many different categorizations. It started out as a comet, was later deemed a planet, was later labelled an asteroid, and then finally was called a dwarf planet in 2006 (the same year Pluto got demoted)!
The name for this dwarf planet comes from the Roman goddess of harvests.
It was first sighted by Giuseppe Piazzi in 1801.
Recent research has demonstrated that the gravity from some of the gas giants (like Saturn and Jupiter) may actually influence Ceres’ orientation. A new study based on NASA’s Dawn mission showed that there have been quite dramatic (in terms of astronomical time!) variations in the axial tilt of Ceres over a course of 24,500 years. This is important because when axial tilt is small, there are some large areas on Ceres that don’t get any kind of direct light from the sun. These “permanently shadowed regions” could possibly have a low enough temperature to allow for frozen water (ice) on the surface of the dwarf planet.
The Kuiper Belt is a very fascinating region of our solar system consisting largely of icy bodies and comets. Thus, there is a lot of really interesting research aiming to better understand the Belt itself and the objects that call it home. One NASA initiative in this regard is the New Horizons spacecraft. This spacecraft, which was launched on January 19th, 2006, made history in July of 2015 when it reached Pluto. The aim of New Horizons was to study Kuiper Belt objects and it held particular concern for Pluto and its moons. Since 2014, New Horizons has made many observations about Kuiper Belt objects and has collected data about the dust and particle environment that makes up this region of space. It has also studied the heliosphere. If it continues along the path that it has, New Horizons is predicted to fly past MU69 (another Kuiper Belt object) on January 1st, 2019. This flyby would set a new record for the farthest world explored in the history of human civilization.
To get you a little excited about this event here are some facts about the Kuiper Belt:
The Kuiper Belt was named after Gerard Kuiper, an astronomer who first predicted the existence of this region of space. It took another 18 years for scientists to find the proof to support this prediction.
The Kuiper Belt extends from about 30 to 55 AU.
The comets in the Kuiper Belt take less than 200 years to fully orbit the sun. On the other hand, long-period comets originate from the Oort Cloud and take longer than 200 years to complete their orbit around the sun.
Climate change is an oft-mentioned topic in a diverse range of conversations including those within the scientific community and increasingly in the political sphere as well. Despite a lot of ongoing talk about climate change, I think that many ordinary citizens, including myself, don’t have a good grasp of the science and math that explains climate change-or how it is measured. In this post, I am going to discuss some of the instruments that NASA and other space agencies use to actually help monitor the health of our own planet’s climate. SAGE (Stratospheric Aerosol and Gas Experiment) I and SAGE II are two instruments that were mounted to satellites that aimed to understand the origins and consequences of the Antarctic ozone hole. In 1987, the Montreal Protocol banned gases that could destroy ozone. The aim of this measure was to recover the ozone layer, which protects the Earth from the sun’s UV radiation. In order to monitor this recovery process, SAGE III was launched to the International Space Station on the SpaceX Dragon capsule in February of this year. SAGE III is expected to remain in use for at least three years. In the past, other instruments have also been launched to help measure and understand climate change. For instance, in 2015, the Cloud Aerosol Transport System was attached to the ISS for the purpose of collected data that can be used in air quality research and climate modelling.
The Earth is around 4.5 billion years old. The first half of the Earth’s existence (prior to the Great Oxidation Event which essentially introduced free oxygen (dioxygen) into the Earth’s atmosphere) was characterized by the presence of certain types of bacteria, although evidence of this existence on our planet is limited. However, last year, researchers from the University of Cincinnati found evidence for this kind of bacteria in fossils found in South Africa. The fossil sulfur bacteria found in South Africa are the oldest known of their kind. The importance of finding such a rare bacterial fossil from this time period (2.5 billion years ago) is that it demonstrates some of the possible ecosystem diversity that may have characterized the Earth’s existence before the GOE. Scientists have previously hypothesized that a supercontinent called Vaalbara may have existed before the splitting up of the tectonic plates of the Earth’s surface. The continent would have included land that now makes up South Africa and Western Australia. This would make sense because it corresponds to where sample fossils of this time are typically found. This particular fossil, according to the University of Cincinnati researchers, may have formed in this supercontinent in a seabed that contained sulfate.
For most contemporary scholars, the modern telescope owes its existence to Enlightenment thinkers who crafted the device to enhance their own stargazing endeavors. However, observing the night sky is hardly a practice that has been limited to the past few hundred years. Thus, it seems likely that there may have been telescopic structures created much before the Enlightenment. For example, there are scholars who believe that the prehistoric Stonehenge in England was designed as a “celestial observatory.” In June of 2016, the Royal Astronomical Society announced that they may have found evidence for stone tomb structures in Carregal do Sal, Portugal that were built six thousand years ago, perhaps for telescopic purposes (specifically stargazing). The tombs (called dolmens) operated by featuring long, but slender, entrances that functioned to “zoom” in on celestial bodies that were not visible by simple, unaided, visual observation. According to the Royal Astronomical Society, it appears that the tomb structures may have been built by prehistoric humans to focus in on the star Aldebaran (part of the Taurus constellation of stars).
Astronomy is one of the oldest sciences. Something about the night sky has fascinated people for centuries. Even in early civilizations, people have demonstrated keen interest in both watching the sky and making observations about the phenomena they observed. Despite its long history, astronomy has evolved over time to reflect new technologies available for observation and study. Perhaps the most fundamental of these innovations was the telescope. Today, technological innovation allows even the most novice of astronomers to make astute observations of the night sky with little more than their cell phone. Generally speaking, astronomy apps that aid in identification of celestial bodies (also called sky-charting apps) rely on a cell phone’s internal GPS to identify where on Earth you are located and use that to create a map of the stars, planets, clusters, and other celestial bodies that are near you. Here is a list of 4 apps that may be relevant to some of the topics that we discuss in this course and will definitely help as you continue to observe the night sky!
Sky Safari uses images from the Hubble Space Telescope and NASA spacecrafts to display a map of the sky at any location-but with a temporal twist. The app is also capable of displaying the position of celestial bodies up to 1 million years from the current date.
Pocket Universe is an app designed to map out the sky that lies in front of a user and gives recommendations for celestial beings that may be visible.
Night Sky 4 is another great sky charting app that is relatively simple to use and is capable of identifying all the usual celestial bodies along with satellites. Furthermore, the visual display of this app includes 3D graphics that can better guide an observer.
The NASA App is slightly different from the apps described above, but can be used as a great resource for information on NASA’s latest activities and missions and provides an enormous amount of information about planets, constellations, and other celestial bodies (along with fabulous videos and pictures of them). Plus, the app is free!
Hi! My name is Niharika and I am a junior MHS major at Vanderbilt. I’m originally from Virginia and I’m looking forward to learning a lot more about cosmic exploration in Astro 2110! The picture above is of my dog Frappuccino and was taken by me!