Author Archives: OliviaZhou

Signs of a super-Earth discovered around Barnard’s star

 

Where is Barnard’s Star? What is Super-Earth?

“Barnard’s star may have a super-Earth”      Source: SciNews YouTube Channel

On November 14th, 2018, astronomers claimed that a super-Earth named Barnard’s star b was discovered in one of the orbitals of Barnard’s star which is a red dwarf star. This indicates that Barnard’s star is faint and has a low mass. It is approximately six light-years away from the solar system, and it is the second closest to the Sun. A super-Earth is an extrasolar planet which has a larger mass than Earth: Barnard’s star b is 3.2 times heavier than Earth and lies in the snow region where liquid water barely exists.

Why Is this finding important?  

The method used to detect Barnard’s star b is called the radial velocity method. It detects the wobbles in a star which are likely to be caused by the gravitational pull of an orbiting planet. This is because wobbles affect the light coming from the star: as it moves towards the Earth, its spectrum appears slightly shifted towards blue, and as it moves away, it is shifted to the red.

“Effect of wobbles on lights”           Source: ScienceNordic

 

 

 

 

 

 

 

The discovery of the planet is vital because it is the first time using this technology to detect a planet having such a small size and such a long distance from its host star. This newly applied radial velocity method adds extraordinary accuracy for identification of a planet. According to Dr. Ignasi Ribas, the research team is over 99% confident that the plant does exist. In the future, however, further data collection is still needed to minimize uncertainties. In addition, the technology is useful and easy to directly observe similar planets and obtain vital info such as the properties of the planets to extend current understanding.

 “Radio Velocity Method for Finding New Planets”      Source: cosmos YouTube  

Why do we keep searching for new planets? 

Due to the explosive growth of population, we are facing the problem brought by the limitation of resource on Earth. Astronomers keep searching for new planets that are Earth-like in the hope of obtaining the signs of liquid water. Moreover, we are all curious about the answer to the question which states “Are we closer to not being alone”.

“Earth-like Exoplanets”                         Source: NASA

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Olivia Zhou

A Decrease of 0.5°C Makes A Big Difference to the World

What is happening?

Video 1: Warnings From New Climate Change Report
Video Credit: CNN Youtube Channel (https://youtu.be/RvaCM1TNBBk)

Three years ago, 195 nations promised to restrain the emissions of greenhouse gas so that the global warming could be limited to 2°C. This year, however, scientists found that 2°C was absolutely not enough, and a target of 1.5°C should be settled.

According to the “New Climate Report” which was released on October 7th by the Intergovernmental Panel on Climate Change (IPPC), a decrease from 2 degrees to 1.5 degrees Celsius changes the world to a great extent. If the goal is achieved by 2100, there will be a significant decrease in heat, drought and sea level rise. Hopefully, there will be fewer loss of species. There are two reasons why scientists published this report: Warning policymakers and calling for a lower warming target.

 

Why is it important?

Video 2: Effects of Climate Change Across the Earth
Video Credit: VideoFromSpace Youtube Channel https://youtu.be/uo80xYqZBiw

The failure of achieving the goal suggested in the “New Climate Report” will affect our daily life. The knotty problem we are facing right now is the increasing number of disasters brought by extreme weather. For example, in February 2018, Vancouver experienced severe snowstorms which caused paralyzed traffic and huge economic loss of the city. These snowstorms occurred due to the La Nina Effect ­– The melting sea ice in the Arctic brought icy waters into the Pacific Ocean and forced the coastal areas to have colder winters than they were before. This also increases the overall sea level and is threatening the existence of island countries such as the Republic of Maldives. In addition, stronger and more intense hurricanes have been attacking the US in recent years. What will be worse, however, is that such climate changes will continue and the weather will become more and more extreme.

Figure 1: Effect of global warming on overall temperature: 1.5°C Versus 2°C
Source: Carbon Brief  

Figure 2: Effect of global warming on drought: 1.5°C Versus 2°C
Source: Carbon Brief 

 

How do we achieve the goal and what are the difficulties? 

It will take approximately 30 years to reduce the emissions of greenhouse gases to zero and reach a balance (between emissions and reductions). Therefore, “negative emissions” which means carbon dioxide removal must be applied to reverse the greenhouse effect.

However, such a reversing process is not straightforward. According to Hausfather, the linear relationship between increasing temperature and carbon dioxide may break if people start removing carbon dioxide out of the atmosphere. Therefore, the scientists from IPPC believed that people must take actions before the climate become even worse and published “Global Warming of 1.5°C” in the hope of changing policymakers’ minds to settle the target of limiting global warming to 1.5°C instead of 2°C.

 

Olivia Zhou