Undersea explorer Victor Vescovo pilots the submarine DSV Limiting Factor in the Pacific Ocean's Mariana Trench in an undated still image from video released by the Discovery Channel May 13, 2019. Atlantic Productions for Discovery Channel/Handout via REUTERS.
An object described by a spokesperson for the Five Deeps Mariana expedition as "manmade" is illuminated at top right by the light of the submarine DSV Limiting Factor on the floor of the Pacific Ocean's Mariana Trench, in an undated still image from video released by the Discovery Channel May 13, 2019. Atlantic Productions for Discovery Channel/Handout via REUTERS.
Sea creatures swim around a part of a submersible lander, illuminated by the light of the submarine DSV Limiting Factor on the floor of the Pacific Ocean's Mariana Trench in an undated still image from video released by the Discovery Channel May 13, 2019. Discovery Channel/Handout via REUTERS.
The Skaff lander floats next to the research vessel DSSV Pressure Drop above the Pacific Oceans's Mariana Trench in an undated photo released by the Discovery Channel May 13, 2019. Atlantic Productions for Discovery Channel/Reeve Jolliffe/Handout via REUTERS.
A technician checks the submarine DSV Limiting Factor aboard the research vessel DSSV Pressure Drop above the Pacific Ocean's Mariana Trench in an undated photo released by the Discovery Channel May 13, 2019. Atlantic Productions for Discovery Channel/Tamara Stubbs/Handout via REUTERS.
The submarine DSV Limiting Factor floats near the research vessel DSSV Pressure Drop above the Pacific Ocean's Mariana Trench in an undated photo released by the Discovery Channel May 13, 2019. Atlantic Productions for Discovery Channel/Tamara Stubbs/Handout via REUTERS.
The submarine DSV Limiting Factor is tethered to a crane from the research vessel DSSV Pressure Drop above the Pacific Ocean's Mariana Trench in an undated photo released by the Discovery Channel May 13, 2019. Atlantic Productions for Discovery Channel/Tamara Stubbs/Handout via REUTERS.