Today, if you are lucky enough to live in the southern hemisphere, there will be an annular solar eclipse. It is going on right now.
https://www.timeanddate.com/eclipse/solar/2017-february-26
26 February 2017
Annular Solar Eclipse on February 26, 2017
25 February 2017
Planetary System around TRAPPIST-1
On February 22, 2017, scientists announced that there were at least seven terrestrial planets orbiting around TRAPPIST-1. Three of them are within the habitable zone. What does this mean for us?
We should learn a little about TRAPPIST-1. It is an M8V star in the constellation Aquarius, approximately 39.5 light-years (12.1 parsecs) from Earth. As an M8V star, it is smaller and cooler than Earth. In 2015, the first three Earth-sized exoplanets were discovered around the star. It wasn't until the recent announcement that they confirmed three of the planets were in the habitable zone. The habitable zone is the zone around a star where liquid water can be found. Look at the post about Earth-like planets to see why both are important.
For a star like TRAPPIST-1, the habitable zone is much closer to the star than it would be for Earth. It is likely that life might be on these planets? No, because these planets are so close to the parent star, and TRAPPIST-1 is very active, if these planets had any atmospheres at one time, they have likely been stripped away. If any life exists, it will be primitive in nature, one-celled lifeforms, if any.
We should learn a little about TRAPPIST-1. It is an M8V star in the constellation Aquarius, approximately 39.5 light-years (12.1 parsecs) from Earth. As an M8V star, it is smaller and cooler than Earth. In 2015, the first three Earth-sized exoplanets were discovered around the star. It wasn't until the recent announcement that they confirmed three of the planets were in the habitable zone. The habitable zone is the zone around a star where liquid water can be found. Look at the post about Earth-like planets to see why both are important.
For a star like TRAPPIST-1, the habitable zone is much closer to the star than it would be for Earth. It is likely that life might be on these planets? No, because these planets are so close to the parent star, and TRAPPIST-1 is very active, if these planets had any atmospheres at one time, they have likely been stripped away. If any life exists, it will be primitive in nature, one-celled lifeforms, if any.
Image courtesy of NASA
As shown in the above image, these are all considered terrestrial planets. They have radii and densities comparable to Earth. They are made up of mostly refractory elements.
31 December 2016
New Year's Eve Comet
If you have access to a telescope or binoculars and you have a clear sky, you may be able to view Comet 45P/Honda-Mrkos-Pajdušáková near the Moon.
See link below.
Comet 45P/Honda-Mrkos-Pajdušáková
See link below.
Comet 45P/Honda-Mrkos-Pajdušáková
06 September 2016
Proxima Centauri B
It has been recently announced that astronomers have discovered a possible terrestrial planet in the habitable zone around the star nearest to the Sun, Proxima Centauri. We discussed a little about Proxima Centarui when we discussed the nearest star system to the Sun, Alpha Centauri.
So what exactly does this mean? Terrestrial planets are those planets much like Earth in terms of size and composition. The habitable zone are the parts of a planetary system where water can be in liquid form on the surface of the planet. Remember, that water is a important to life in the universe.
Now, having a Earth-like planet in the habitable zone does not necessarily mean that the planet has water. We won't know for a long time, either.
So what exactly does this mean? Terrestrial planets are those planets much like Earth in terms of size and composition. The habitable zone are the parts of a planetary system where water can be in liquid form on the surface of the planet. Remember, that water is a important to life in the universe.
Now, having a Earth-like planet in the habitable zone does not necessarily mean that the planet has water. We won't know for a long time, either.
10 July 2016
July
July is the 7th month in both the Julian and Gregorian calendar. It has 31 days, and is one of the hotter months of the year in the northern hemisphere. We are going to discuss a little about the naming of the month.
In the Roman calendar, there used to be only 10 months, and July was the fifth month. It was original named Quintilis, which is Latin for fifth. When the Roman calendar changed to a 12-month calendar, it retained the name Quintilis. We will see more of this later on when we talk about the final four months of the year.
In 45 BCE, when the Julian calendar was introduced, then Roman dictator Julius Caesar had the calendar created to follow more along the lines of the actual orbit of the Sun. When he was assassinated the following year, they renamed Quintilis Julius after Caesar, and it was anglicized to July.
In the Roman calendar, there used to be only 10 months, and July was the fifth month. It was original named Quintilis, which is Latin for fifth. When the Roman calendar changed to a 12-month calendar, it retained the name Quintilis. We will see more of this later on when we talk about the final four months of the year.
In 45 BCE, when the Julian calendar was introduced, then Roman dictator Julius Caesar had the calendar created to follow more along the lines of the actual orbit of the Sun. When he was assassinated the following year, they renamed Quintilis Julius after Caesar, and it was anglicized to July.
30 June 2016
Leap Second
Everyone knows the leap day. Every four years (except century years not divisible by 100), an extra day is added to the year in February to keep the calendar in synch with the seasons.
However, there is also a leap second. This is used every couple of years to keep the Coordinated Universal Time close to the mean solar time. The reason why it is needed is that the Earth's rotation is slowing down, but not by a lot.
The second is added just before midnight on either June 30th or December 31st. The time would go from 23:59:59 to 23:59:60 to 00:00:00. The last time a leap second was added to the UTC was last June 30th.
However, there is also a leap second. This is used every couple of years to keep the Coordinated Universal Time close to the mean solar time. The reason why it is needed is that the Earth's rotation is slowing down, but not by a lot.
The second is added just before midnight on either June 30th or December 31st. The time would go from 23:59:59 to 23:59:60 to 00:00:00. The last time a leap second was added to the UTC was last June 30th.
28 June 2016
Negative Energy
Energy is what is called a scalar in physics. A scalar is a measurement that has a magnitude, but not a direction. Distance and time are other examples of a scalar. Vectors are measurements that have both magnitude and direction. Acceleration, force, and velocity are all examples of vectors.
Note: velocity and speed are not interchangeable in physics. Speed is a scalar, velocity is a vector.
Why is this important to know that energy is a scalar? Scalars are generally always zero or positive. So typically, the energy of a system is always zero or greater. The concept behind negative energy is this:
Suppose you have two objects separated by an infinite distance. The sum total of their energies is zero. Gravitational force then accelerates the two objects together. Therefore, the energy the system is increasing. But a closed system cannot change its energy. Therefore, the difference between the initial condition and the final condition is negative, hence negative energy.
Negative energy is a strange concept to understand and it's only theoretical since the above situation is very simplistic. However, if it does exist and we can harness it, negative energy can lead to humanity colonizing the galaxy (well, at least the local neighborhood). Negative energy can impact warp drives and may be used to stabilize wormholes.
Note: velocity and speed are not interchangeable in physics. Speed is a scalar, velocity is a vector.
Why is this important to know that energy is a scalar? Scalars are generally always zero or positive. So typically, the energy of a system is always zero or greater. The concept behind negative energy is this:
Suppose you have two objects separated by an infinite distance. The sum total of their energies is zero. Gravitational force then accelerates the two objects together. Therefore, the energy the system is increasing. But a closed system cannot change its energy. Therefore, the difference between the initial condition and the final condition is negative, hence negative energy.
Negative energy is a strange concept to understand and it's only theoretical since the above situation is very simplistic. However, if it does exist and we can harness it, negative energy can lead to humanity colonizing the galaxy (well, at least the local neighborhood). Negative energy can impact warp drives and may be used to stabilize wormholes.
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