The Mars rover Curiosity, which reached the base of Mount Sharp earlier this month, has started drilling into the Red Planet’s surface- and also found an unusual rock the size and shape of a golf ball.

For anyone who remembers the Seinfeld episode where Kramer hits golf balls off the roof, it’s unfortunately not one of his; the spherical rock, which resembles a dusty tennis ball, is a natural phenomenon.

Golf balls aside, the Curiosity drilled 2.6 inches into Mars’ rocky surface, collecting the pulverized dust with a series of instruments designed to collect soil samples. This was the Curiosity’s fourth drill of the Martian landscape.

Mount Sharp has long been a target of interest due to its wealth of rock layers, which could help scientists understand the planet’s geological history and subsequent loss of water. While the mountain was originally supposed to be explored months ago, the mission was sidetracked by the exploration of Yellowknife Bay, a dried-up lake that was found to have been suitable for primitive microorganisms.

According to Curiosity Deputy Project Scientist Ashwin Vasavada of NASA’s Jet Propulsion Laboratory, “This drilling target is at the lowest part of the base layer of the mountain, and from here we plan to examine the higher, younger layers exposed in the nearby hills. This first look at rocks we believe to underlie Mount Sharp is exciting because it will begin to form a picture of the environment at the time the mountain formed, and what led to its growth.”

While the Curiosity rover is studying Mars’ soil, NASA’s Maven spacecraft- short for Mars Atmosphere and Volatile Evolution- entered Mars’ orbit a few days ago. Maven is designed to collect valuable information regarding the Red Planet’s upper atmosphere. Additionally, a satellite was recently launched from India towards Mars to conduct additional atmospheric research.