The bright light Monday evening that turned out to be a research balloon was part of a program called NASA HASP (high altitude student platform).
And it was carrying an ASU research project.
"This is simply a helium balloon that goes up to about 36 kilometers and stays there for 24 hours, and then comes down," said Sri Saripalli, ASU professor of Earth and Space Exploration.
The balloon carrying ASU's experiment tested two different solar collection methods and compared their efficiencies at high altitude.
"This experiment consisted of various solar panels. One that was stationary and one that was tracking the sun," Saripalli said.
And not to worry - the huge balloon will not wind up in your yard.
Monday's balloon ultimately came down in the desert southwest of Wickenburg.
"When they terminate the experiment, when the balloon drops and the payload drops, they make sure it's in a completely deserted part of the country," said Saripalli.
Although these type of experiments can also be done on high altitude NASA aircraft, balloons are much less expensive.
"Balloons really get you close to space and if you want to do long-term experiments, balloons are the way to go about doing this," added Saripalli.
So don't be surprised if you see more of this bright light in the sky for years to come.
"Valley residents will certainly see this once every year. This happened last year also and this will happen next year and hopefully the year after that and the year after that," Saripalli said.
The ASU School of Earth and Space Exploration said they won't know the results of the experiment for at least another two weeks.
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