Astronomers are taking a closer look at what could be clouds Pluto's the low altitude haze layer. (NASA/JHUAPL/SwRI)

When NASA's New Horizons spacecraft sent back the first high-definition images of Pluto, the world was captivated. After having some time to get a closer look, astronomers have uncovered newfeatures that add to the argument that Pluto should become a planet once again.

Astronomer Will Grundy of the Lowell Observatory in Arizona took a closer look and found bright spots that appeared to be clouds hovering above the jagged landscape, New Scientist reports.

However, the clouds may not be clouds as we know them. They're likely consistent with the rest of Pluto's atmosphere: nitrogen, methane, acetylene, ethylene and ethane.

Either way, the photos illustrate a complexity in Pluto's atmosphere that many think qualify it to be upgraded to a full-fledged planet 10 years after it was downgraded.

(MORE: Scientists Discover What Appears to Be Flowing Ice, Hazy Atmosphere on Pluto)

Pluto has multiple hazy layers in its atmosphere, which mostly consists of nitrogen. (NASA/JHUAPL/SwRI)

The presence of clouds would indicate that Pluto has an active cycle, an exciting prospect for astronomers.

"In the Earth's atmosphere a cloud is produced by water droplets in suspension in the atmosphere," Martin Barstow, the president of the Royal Astronomical Society, told MailOnline. "We could be seeing a similar effect - but not with water, as the temperature is too low - or it could be that the clouds are forming because of emission of material from the surface, so we are seeing a region which has more gas and looks more opaque than the surroundings."

Neither a cloudy atmosphere nor an active cycle are included in theconditions for planethoodagreed upon by the International Astronomical Union (IAU). To be a planet, the body must circle the sun without being a satellite to another space object; have a round shape formed by gravity; and must have "cleared the neighborhood around its orbit." Pluto fails the last test because it is surrounded by the Kuiper Belt.

(MORE: NASA's New Horizons Captures Thrilling First-Ever Photos of Pluto's Small Moons)

But even the head of the New Horizons team, Alan Stern, thinks those conditions are too complicated. "It shouldn't be so difficult to determine what a planet is," he said in a 2009 interview with Space.com.

But Barstow called the idea of a reinstatement "a bit misleading," because other non-planet celestial bodies, like Saturn's largest moon Titan, have active cycles.

The photos of Pluto from the New Horizons mission came out months ago, but it's clear they will continue to provide clues to the dwarf planet.

MORE ON WEATHER.COM: Amazing Photos of Pluto from the New Horizons Mission

New Horizons scientists made this false-color image of Pluto using a technique called principal component analysis to highlight the many subtle color differences between Pluto's distinct regions. The image data were collected by the spacecraft’s Ralph/MVIC color camera on July 14 at 11:11 AM UTC, from a range of 22,000 miles (35,000 kilometers). (Credits:NASA/JHUAPL/SwRI)