Questioning the existence of aliens is something that scientists have done for decades. In fact, most people do believe that aliens exist in some fashion. The main necessities for life are water and some form of energy source. Not surprisingly, there are some planets, exoplanets and moons that fit the bill. Here are several best chances at finding life in the universe.

◆TRAPPIST-1

TRAPPIST-1 is a planetary system a few dozen light-years away, whose discovery was announced in early 2017. This system consists of seven Earth-like exoplanets orbiting an "ultra-cool" star, and it is one of our shots at finding possible life beyond our own solar system.   

◆Titan

Titan is the largest moon of Saturn, the sixth planet from our Sun. This moon could potentially harbor life but possibly not in the sense that we think. Titan does not exactly fit the description of being in a typical habitable zone.

Titan has water, and it has liquid. It just doesn't have liquid water. The water on this moon is completely solid because of the extremely cold temperature.

◆Europa

Europa is one of Jupiter's moons here in our own solar system. It is another candidate due to its potential to hold liquid water. Europa is thought to have all the necessities for life including water, energy sources, and the right chemical build-up.

◆Mars

The Red Planet, the fourth from the Sun, is probably one of the most talked-about potential candidates for extraterrestrial(地球外的) life and even for human colonization. Despite some different voices, finding extraterrestrial life on Mars really is a serious possibility.

We know by now that we won't find little green men or any intelligent form of life that we understand. However, there is evidence that there was and may still be microscopic life on the small red planet.

When he was young, Louis Armstrong was taking what was called “Creole jazz”, which was also called dance music, and combining it with trumpeter(小号手) Buddy Bolden, to create what would eventually become today’s jazz.

Armstrong accomplished this with almost no formal training. He received little training before he was placed in the New Orleans Colored Waif’s Home at the age of 12, after a run-in(小争执) with the police. The punishment turned out to be a mixed blessing, for he also had the opportunity to play in a real band.

While at the Waif’s, Armstrong also got the chance to hear some of the city’s finest musicians. Cornetist Freddie Keppard performed in a nearby club. So did trumpeter and bandleader King Joe Oliver, who took the boy under his wing and taught him how to read music and work on his playing technique.

When Oliver left for Chicago, Armstrong chose to stay in New Orleans and work with some of the other top musicians of the day. In Chicago, King Oliver offered him a place in his band in 1922. It became Armstrong’s biggest challenge yet — the band had no parts written for trumpet, so he was forced to listen to King Oliver and improvise(即兴创作).

Soon, Armstrong’s undeniable talent was getting noticed. Even classically trained musicians would come to hear the incredible sounds this young man created.

Lil Hardin, the band’s piano player and the future Mrs. Armstrong, explained that Oliver kept Armstrong in the second trumpet-chair so that Oliver would still be “King”. Hardin convinced him to leave the band.

Armstrong moved to New York City in 1924 to join Fletcher Henderson’s band and then flew solo. In 1925, Armstrong put together the Hot Five, expanding his popularity even more. Armstrong recorded his first composition, Cornet Chop Suey, one of the most copied jazz solos of all time. This monumental 1928 recording blends(混合) artistry, endurance and showmanship that has rarely, if ever, been matched in jazz.

Have you ever felt so tired after staying up for a night that even coffee doesn't give you the energy that you need? You may have an energy drink, but the benefits of drinking one are heavily outweighed by the risks.

In the past years, more and more studies have found the deadly effects of energy drinks on our bodies. The sugar, caffeine and energy supplements (补充)in energy drinks make up a deadly mixture of ingredients that can affect your heart function and send you to the hospital!

A study by the University of Bonn, Germany found that frequent consumption of energy drinks can greatly change the way our heart functions. The study went on to say that consuming energy drinks often causes significantly increased heart contractions in adults, which has the potential of putting you at risk for irregular heartbeats.

It is possible that many people are unconscious of the alarming side effects of energy drinks because of the way they are labelled. Most energy drinks contain between 80 milligrams to over 350 milligrams of caffeine, sugar and energy supplements. When an energy drink is marketed as a diet supplement, it may be distributed without a "nutrition facts" label, which would show the harmful supplements that are in the drink. However, even if energy drinks are Food and Drug Administration (FDA) approved, they don’t have to show the number of supplements.

Energy drinks may be widely available but they aren't the healthiest or safest choice for your body. To stay naturally energized, get organized and stay on top of your work so that you aren't having to stay up all night to complete assigned tasks. If you'd like a natural energy boost, you could make time for a short workout, which will give you all of the energy you need!

The Illinois Department of Natural Resources is returning a fish called the alligator gar to the state's rivers. Some people call the fish a “living fossil." Experts believe the fish first appeared during the Early Cretaceous period more than 100 million years ago.

Randy Sauer is an Illinois state fisheries biologist. He says the fish disappeared from the state's rivers in the 1990s, although they have continued to do well in southern states. Sauer says biologists want to bring the fish back to northern rivers "because it is important to have top predators （捕食者）to balance the species below them," he said.

Sport fishermen like to try to catch the alligator gar. Alligator gar are the second-largest freshwater fish in North America. They can grow as large as 2,7 meters and weigh more than 136 kilograms. Sauer says their large size is one reason they disappeared in the 1990s. Experts say alligator gars are '"opportunistic feeders." This means they will eat almost anything — including small turtles or ducks. They also eat invasive species such as Asian silver carp. Sauer hopes the reintroduction of the alligator gar will help the state's efforts to control the carp. Because alligator gar can live up to 60 years, the program will continue to increase for many years.

Sauer notes that female alligator gars do "not sexually mature until 11 years, and the male not till 6 or 7 years' That means the biologists will try to raise and release a lot offish early in the program to reintroduce them. “We're probably going to stock （储备）more heavily than 10 or 20 years down the road when hopefulIy these fish will find each other and start doing the job on their own." Sauer says.

Small devices have been placed in 7,000 of the fish so they can be observed after they are released into the waterways of Illinois. As it rains and floods, biologists expect some of the fish will follow the rivers into the states of Louisiana and Texas.