very exciting because 95% of the methane on earth is produced by biology produce from termites, rice patties, cows, or sheep. because of that, there's an interest in mars methane the potential biological origin. that's true because we know it can only last for 300 years. so if you see it something is being released or created. i'll hand over to paul for the second part. >> on earth, like chris mention, most comes from the biology of rice patties and a lot of different processes. most of the oxygen on earth comes from biology, billions of years ago the bright bacteria started cranking away. in our atmosphere we have methane and oxygen. that's what some of the folks will be looking for combinations of oxidizing that might be evidence of light. >> we have another question for the media. >> the next is nancy. >> hello, there is a similar announcement methane and organic materials in 2014, how is this announcement different? or how have you built on the findings from 2014? >> 's a very good question. in 2014 we reported the discovery of coordinated molecules. it was a significant discovery. the f

i have a chicken patty, chicken and rice. >> reporter: ...every meal comes with a "sweetie pie." >> allrter: auntie debra, as she's known here at hoover high school, doles out a heaping level of hospitality every lunch hour. >> see you all tomorrow! >> reporter: after serving food all day-- >> i come out here. >> reporter: after lunch, debra drives her beat-up '76 chevy malibu all over san diego, looking for hungry homeless aople. >> hey, how are you? >> reporter: i think she's okay. >> no, she's not! >> reporter: debra says she never met a homeless person who wasn't starving for her home cooking. >> c'mon, tell them to come and eat. >> reporter: on this day, she served more than 50 multicourse meals. >> pork, carrots and rice, rdllard greens with smoked turkey... >> all at her own expense. >> barbecue ribs. >> reporter: areou >> ...no. >> reporter: i took that as a "yes." you're spending money you don't have. >> yes, but what you don't understand the joy that i get from feeding people. tomorrow is spaghetti and meatballs, okay? >> reporter: because debra is so selfless, recently the sc

patty. chicken and rice. >> every meal comes guys sweetie pie. >> aunty deborah as she's known dolls out a heapingpitality every hour. >> see y'all tomorrow. >> after serving food all day. >> i come out here. >> after lunch she drives her beat up '76 malibu all over san diego looking for hungry homeless people. >> hey bay. >> how are you. >> think she's okay. >> no she's not. >> she never met a homeless person who wasn't starving for her home cooking. >> tell them come over here and eat. >> on this day served more than 50 meals all at her own expense. >> barbecue ribs. >> are you broke. >> no. >> i took that as a yes. >> you're spending money you don't have. >> yes but -- you don't understand the joy that i get from feeding people. >> tomorrow's spaghetti and meat balls okay. >> because deborah is so selfless recently the school district invited her down not auto shop and surprised her with friends and family and some better wheels to deliver those meals. this 2014 mazda 3 was refurbished by an auto body class in the district. >> i'm not used to a new car y'all. >> she was so flabbergasted tedn't